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Graphite Valley Industrial Group
Five years! Graphite Valley Industrial Park from the breeding of new "ene" to build a billion-level enterprise

Five years! Graphite Valley Industrial Park from the breeding of new "ene" to build a billion-level enterprise

Mar 07,2022

The production line in the workshop is running at high speed, and the construction site is busy. A few days ago, when the reporter walked into Jubao Third Road in Harbin New District, he felt a lot of vitality. Construction and production Products sold to well-known enterprises at home and abroad In the park, a graphite original stone road with the word "ink" engraved with different fonts extends in the park, indicating that this is a world related to graphite. Next to the graphite stone road, there is a 7-storey graphite (ene) new materials research institute building, and some of the floors where the equipment has been installed are undergoing experiments. "This is currently the largest, most complete, and most specialized graphite (ene) research institute in China." Provincial Graphite Valley Industry Group Co., Ltd. Chairman Fang Zhenhui said. Walking into the graphene production line workshop behind the research institute building, the reporter did not hear the noisy machine sound, and could hardly see the staff. He saw multiple stainless steel tanks lined up to form a production line. Under the operation of the computer, natural flake graphite "enters" the production line, and after "coming out", it is graphene worth a hundred times. From flake graphite to graphene, the value has increased from several thousand yuan per ton to one million yuan per ton, realizing the magnificent transformation from "civilian" to "noble. "Graphene is called 'black gold' and is the 'king of new materials '". Fang Zhenhui told reporters that with the help of magical graphene, revolutionary breakthroughs will be triggered in the fields of national defense equipment, aerospace, new energy vehicles, flexible mobile phones, and super batteries in the future, and will drive an emerging industrial chain worth trillions of yuan. With the introduction of Fang Zhenhui, the development path of Graphite Valley Industrial Park is clearly visible. On October 16, 2015, the foundation of the Graphite Valley Industrial Park project was laid. For more than 5 years, the project has been producing while building. With the production line of graphene composite conductive slurry with an annual output of 10000 tons and the official operation of the Graphite (ene) New Material Research Institute, the construction, research and development, and production of the Graphite Valley Industrial Park, Sales go hand in hand. At present, driven by technological innovation, Graphite Valley Industrial Park has formed four series and 15 categories of products of graphite anode materials, graphene materials, carbon nanotube materials and intelligent equipment in the fields of new energy and new materials, and has become the top lithium ion battery and power battery supplier at home and abroad such as LG, Ningde New Energy, Guoxuan Hi-Tech, Peng Hui and Tianjin Lishen in South Korea, and successfully imported the supply system of Volkswagen, Tesla and Apple. In 2020, under the severe impact of the epidemic, the company achieved sales of nearly 0.1 billion; in the first quarter of this year, it achieved an output value of 31 million billion yuan, up 280 percent year-on-year, and is expected to exceed 0.2 billion billion yuan for the whole year. Standing on the shoulders of giants Rapid growth as industry leader At the beginning of its establishment, Graphite Valley Company was jointly established by China Baoan Group and its holding subsidiary Beitri New Materials Group Co., Ltd. and Harbin Institute of Technology. to build an innovative national high-tech enterprise focusing on the research and development, production and sales of graphite, graphene, carbon materials and their applications. "With the accumulation of years of research and development results from Shenzhen Bertrand, Peking University and Harbin Institute of Technology, we have ensured the company's continued technology and market leadership. It can be said that we are a growing enterprise standing on the shoulders of giants." Fang Zhenhui told reporters that since the beginning of the project, Bertray has imported talents and technological research and development achievements into Graphite Valley and helped to open up the market, which has made Graphite Valley develop faster. After five years of development, the Graphite Valley Industrial Park has become one of the world's leading suppliers of graphene and carbon nanotube conductive materials for lithium-ion batteries. At the same time, it is also the main drafting unit of the national standard of graphene, and is a leading enterprise in the graphite new material industry recognized by the provincial government. Multiple projects at the same time Build ten billion level enterprise group This year, the Graphite Valley Industrial Park entered a high-speed growth period. "Heilongjiang is the province with the largest graphite reserves and the best quality in China. We should shoulder the obligation of improving the scientific and technological level of graphite and the added value of products in Longjiang, and change the history of Longjiang holding a 'golden bowl' and eating 'coarse grain." Fang Zhenhui said that at present, Graphite Valley has built a total of 5 graphite new material industrialization projects, with a total investment of nearly 0.6 billion yuan. Among them, the Graphite (ene) New Material Research Institute that has been built is embarking on the next generation of graphite anode materials, graphene coatings, and polymer The research and development of composite materials, single-walled carbon nanotubes, and graphite intelligent complete sets of production equipment. It is reported that at present, the procurement of equipment for the production line of a new generation of high-performance carbon nanotubes has been completed and is expected to reach 1,000 tons of production capacity this year. The graphite equipment manufacturing production line project has been capped and is currently under internal decoration. It is expected to be put into normal operation in June. The production line of anticorrosive coating and fire retardant coating is waiting for the equipment to be installed and debugged, with a production capacity of 5000 tons in June. In the next five years, while continuing to improve the above five projects, the company will start the artificial graphite project and the natural graphite project, with a total planned investment of 4.4 billion yuan. Among them, the key artificial graphite project is to cooperate with Daqing municipal government, with a planned investment of 2.65 billion yuan. After the completion of the project, it will become the first industrial chain industrial park of new artificial graphite materials in our province from crude oil smelting coke, research and development, deep processing to applied materials, filling the gap in this field in our province. The natural graphite project is in cooperation with Shuangyashan municipal government, with a total investment of 1.75 billion yuan. After the project is completed, it will become the only natural graphite new material industrial park in China with the whole industrial chain of mining, mining, deep processing and application products. "Graphite Valley Industrial Park has been called Harbin Wanxin Graphite Valley Graphite (ene) New Material Industrial Park since its landing, and the name of our company is Harbin Wanxin Graphite Valley Technology Co., Ltd., or Wanxin Graphite Valley for short. In January this year, the company was upgraded to Heilongjiang Province Graphite Valley Industry Group Co." Fang Zhenhui is full of confidence in the future. "by 2025, the company will strive to form a 10 billion-level industrial group and complete its IPO, becoming the first graphite stock in China and the first valley in the graphite industry."

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Graphite Valley Industry Group "March 8th Women's Day" Theme Activities

Graphite Valley Industry Group "March 8th Women's Day" Theme Activities

Mar 08,2022

In order to celebrate the arrival of "March 8th International Women's Day", on March 8, the trade union of Graphite Valley Group launched the theme activity of "March 8th" to celebrate the exclusive "goddess" festival in a special way. Full of warmth, warm blessing The company leaders offered good wishes and holiday greetings to the "goddesses", sent carefully prepared gifts, thanked them for their contributions to the development of the company, and wished everyone a happy holiday, a happy family and a smooth work. Mother, wife, daughter, colleague, lover ...... No matter what kind of status, where you live, you are the most beautiful color in the world. The spring breeze blows across the face in March. Even if the peach blossom is beautiful, it is not as beautiful as your smile. When you are gentle, the years are amazing. The smooth development of the "March 8th Women's Day" theme activity not only conveyed the cordial greetings and heartfelt wishes of the company to the majority of female employees, but also effectively increased mutual exchanges and communication; in the next step, the company's labor union will continue to carry out various activities, Fully mobilize the enthusiasm of female employees, and form a good atmosphere for female employees to devote themselves to their posts, work hard in their posts, and make contributions in their posts, to contribute to the company's high-quality development of women's wisdom and strength.

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I Graphite Valley Industry Group Held First Quarter Work Summary Meeting

I Graphite Valley Industry Group Held First Quarter Work Summary Meeting

Apr 18,2022

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Current Situation of Spherical Graphite Industry

Current Situation of Spherical Graphite Industry

Apr 27,2022

Spherical graphite is a high-quality high-carbon natural flake graphite as raw material, the use of advanced processing technology to modify the surface of graphite, the production of different fineness, shaped like an elliptical spherical graphite products. The standard of "Spheroidized Natural Graphite" (JC/T 2315-2016) is applicable to spherical or spherical graphite products made from natural flake graphite and processed by mechanical and physical methods, and points out that the physical and chemical properties of spheroidized natural graphite should meet the following requirements Spherical graphite has the advantages of good conductivity, high crystallinity, low cost, low charge and discharge potential and flat, long cycle life, green environmental protection and other characteristics, has gradually become the replacement of lithium-ion battery production of anode materials. At present, China has successfully applied the development of natural flake graphite raw materials to adapt to the production of lithium-ion batteries, that is, the modified products of spherical graphite, so the lithium-ion battery industry chain has entered a new era. According to the data, in 2020, China's lithium battery anode material market size increased to 14.02 billion yuan, 2016-2020 annual compound growth rate of 21.4, is expected to reach 15.91 billion yuan in 2021, shipments increased to 36.5 tons in 2020, is expected to reach 40.1 tons in 2021. At the same time, in the past five years, the domestic spherical graphite industry market average price overall downward trend, by 2020 the average price fell to 17800 yuan/ton, which will greatly reduce the production cost of lithium-ion battery anode materials to a certain extent. In summary, with the continuous expansion of lithium-ion battery anode material shipments and market scale, it will continue to drive the demand and sales growth of spherical graphite. According to the data, in 2020, China's spherical graphite industry sales of 112000 tons, is expected to reach 124000 tons in 2021; sales revenue of 1.949 billion yuan, 2016-2020 compound annual growth rate of 16.8, and is expected to reach 2.207 billion yuan in 2021. In addition, the United States, the United Kingdom, the European Union and other countries or regions have gradually realized the key role of graphite in energy transformation and environmental protection, and issued a series of policies to gradually make graphite a strategic resource. However, the Ministry of Industry and Information Technology of China also issued the "Standard Conditions for Graphite Industry" in 2020, which clearly no longer pursues quantity and deleted the scale indicators such as "the design scale of new and expanded flake graphite beneficiation projects shall not be less than 20000 tons/year", which will be implemented from June 24, 2020, while the "Access Conditions for Graphite Industry" issued in 2012 will be abolished at the same time. By comparing the two documents, it can be found that the protection of graphite in the new edition of the conditions is obviously upgraded, which is suitable for the strategic protection of resource status. Therefore, the promotion of the strategic position of graphite resources at home and abroad will provide a better policy and social foundation for the spherical graphite industry and promote the rapid development of the industry.

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Technology Development | Subversive Achievements of Professor Hu Xiaojun of Zhejiang University of Technology

Technology Development | Subversive Achievements of Professor Hu Xiaojun of Zhejiang University of Technology

Apr 27,2022

The team of Professor Hu Xiaojun of Zhejiang University of Technology innovatively "restored" the growth process of chemical vapor deposition diamond, and realized the point "stone" into "drill" under low pressure, which provided a new strategy and theoretical basis for the synthesis of large-area diamond. When it comes to diamonds, many people first think of dazzling diamonds. In fact, the application of synthetic diamond in industrial production is also "dazzling". It has all the excellent properties of natural diamonds and is widely used in precision cutting tools, wear-resistant devices, semiconductors and electronic devices, low magnetic detection, biomedicine and so on. At present, there are two main types of industrial synthesis of synthetic diamond: high pressure and high temperature method and chemical vapor deposition method. However, due to the limitation of high temperature and high pressure equipment, it is still difficult to prepare large-size single crystal diamond; chemical vapor deposition needs to grow single crystal diamond with natural single crystal diamond as the substrate, and natural single crystal diamond is limited by area, still can not prepare large-area diamond, which greatly limits the application of artificial diamond. The team of Professor Hu Xiaojun of Zhejiang University of Technology has long focused on the research work of diamond films and nano-carbon materials, and is committed to exploring the preparation, doping new methods and photoelectric properties of diamond films and other materials. The research team is concerned that compared with graphite, the thermodynamically metastable diamond can be formed under the low pressure of chemical vapor deposition, and its unique formation mechanism may contain a way to synthesize large-area diamond. However, the growth environment of chemical vapor deposition is complex and it is difficult to achieve in-situ characterization, so the formation mechanism of diamond in the deposition process has always been a difficult problem for scientists in the field of materials. Hu Xiaojun's team used the slow growth method to "restore" the growth process of chemical vapor deposition diamond. The team used "cauliflower"-shaped nano-diamond particles as templates and adopted a series of short-term growth strategies to form instantaneous thin layers. Through direct observation of scanning electron microscopy, Raman spectroscopy and high-resolution transmission electron microscopy, the surface morphology and microstructure of a series of thin layers grown on the "cauliflower"-shaped template at short intervals of 30 seconds at a growth power of 1800 watts were obtained, it was found that the nano-diamond matrix-the initial growth of erect graphene-the growth of erect graphene-the bending of erect graphene into needle-like graphite-the disappearance of needle-like graphite-the recovery of the nano-diamond matrix cycle. This is the first time that the cyclic appearance of graphite/diamond has been found in the chemical vapor deposition process. So how does this process occur? One conjecture is that graphite and diamond grow in turn, and the diamond is covered with graphite after it grows; if so, a large amount of graphite should still be observed in the Raman spectrum after diamond formation, but the actual situation is that the Raman characteristics of the sample are typical of nanodiamond films; To further confirm this never-before-reported phenomenon and the bold conjecture that graphite turns into diamond, the team reduced the growth power to 1600 watts and extended the growth time to 12 minutes to slow the growth rate to capture clearer evidence of graphite turning into diamond. In the 4-minute sample, the main component is relatively straight graphene (Fig. 4b), which changes to graphite nanoneedles (Fig. 4d) at 8 minutes. This nanoneedle contains both graphite (002) and diamond (111) facets (Fig. 4d). When the time was extended to 12 minutes, the graphite disappeared completely, and a large number of diamond grains were observed in the sample (Fig. 4f), indicating that the graphite had been completely converted into diamond. This indicates that the 8 min sample with both diamond (111) and graphite (002) crystal planes is an intermediate transition state for the conversion of graphite to diamond. Further analysis of the structural evolution of this transition state (Figure 4g) shows that graphite (002) is found in the head region 1 of the sample in 8 minutes, a new and darker diamond crystal plane (0.21 nm) appears in the middle region 2 covering the graphite (002) crystal lattice, and the diamond crystal plane (0.21 nm) in the middle region 3 enhances the graphite (002) to weaken, in the root region 4, the graphite (002) lattice disappears and the diamond (0.21 nm) lattice becomes the host lattice. This clearly demonstrates the gradual conversion of graphite to diamond, as shown in Schemes 4j and j-1. It can be seen that in the process of chemical vapor deposition, the formation of diamond is from the phase change of graphite, which subverts the traditional concepts of "active carbon atoms piled up into sp3 diamond lattice" and "sp2 graphite carbon phase is the 'carbon rubbish' in the growth process of diamond film, which is removed by hydrogen etching in the atmosphere.

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"Visiting Enterprises to Tougang" Entering New District, "School-land Cooperation" Promoting Employment! Wanxin Graphite Valley Attends Online Docking Meeting between New District and Harbin Normal University

"Visiting Enterprises to Tougang" Entering New District, "School-land Cooperation" Promoting Employment! Wanxin Graphite Valley Attends Online Docking Meeting between New District and Harbin Normal University

Apr 30,2022

On the afternoon of April 29, Harbin Wanxin Graphite Valley Technology Co., Ltd. participated in the 44th issue of the school-land cooperation online docking meeting jointly organized by Harbin New District Party Working Committee, Harbin New District Management Committee and Harbin Normal University on Friday, focusing on the theme of "visiting enterprises to expand their posts" and "school-land cooperation" to promote employment. Member of the Party Working Committee of Harbin New Area, Member of the Party Working Committee of the Harbin Area of the Free Trade Zone, Wan Bingrui, Member of the Standing Committee of the Songbei District Committee and Minister of the Organization Department, Yu Hong, Director of the Development and Reform Bureau of Harbin New Area, Guo Li, Deputy Secretary of the Party Committee and Chairman of the Labor Union of Harbin Normal University And relevant college heads attended the meeting. Wanxin Graphite Valley with Zhongke Yingjiang, University of Technology Software, Gushi Biology, Hailingke, Chaoxi Wenchuang and other 6 enterprises to participate in the meeting. The meeting was presided over by Cheng Huaiqiang, general manager of Harbin New District Human Resources Service Co., Ltd. At the meeting, Wan Bingrui, member of the Standing Committee of the Songbei District Party Committee and Minister of the Organization Department, first introduced the overall development of the Harbin New District and the various talent policies and implementation of the New District. Minister Wan said that in recent years, Harbin New area has a strong momentum of development and is in a period of historical opportunity of "superposition of five districts." the demand for talents in the development of enterprises is more urgent than ever before, and college graduates will get a broad space for development in the new area. It is hoped that through today's activities, Harbin Normal University can find cooperative enterprises suitable for students' internship and employment, and graduates can get more opportunities to display their talents and let more outstanding talents stay in the new area. In the school promotion session, Guo Li, deputy secretary of the Party Committee of Harbin Normal University, first introduced the school's general situation and student source information to the leaders of the new district and corporate guests attending the meeting. Secretary Guo said that there are nearly 10,000 graduates of the 2022 class of Harbin Normal University. Harbin New District is an important area for normal university graduates to stay in the province for employment. He hopes to further build a cooperation platform, establish a benign interaction mechanism, and carry out pragmatic, efficient and long-term in-depth docking., Give full play to the advantages of school-local, school-enterprise cooperation, and carry out more extensive, in-depth and lasting cooperation in talent training, internship, innovation and entrepreneurship. After the introduction of Secretary Guo, Zhou Guohui, Dean of the School of Computer Science and Information Engineering of Harbin Normal University, Chang Weidong, Secretary of the Party Committee of the School of Chemistry and Chemical Engineering, Deng Tienan, Secretary of the Party Committee of the School of Management, Si Hong, Secretary of the Party Committee of the Academy of Fine Arts, and Yang Shoubin, Secretary of the Party Committee of the School of Media, respectively introduced The overall situation of each college, the data of each major graduates, the data, the results, awards, professional settings and resource advantages. In the enterprise promotion link, Harbin Wanxin Graphite Valley Technology Co., Ltd., together with the other five enterprises, made a detailed introduction to the development situation, employment demand, salary and welfare treatment and talent training plan of their respective enterprises. At the meeting, Wanxin Graphite Valley made it clear that it is willing to provide interns and fresh graduates with well-paid jobs and internship and practice opportunities, especially technical research and development and marketing positions, so as to jointly develop a mutually beneficial and win-win situation for school-enterprise cooperation. At the end of the meeting, both schools and enterprises expressed their great expectation for offline docking activities after the stabilization of the epidemic, and thanked the new district for schools and enterprises to bridge the issue of enterprises during the epidemic to solve the urgent need for talent and graduates internship employment difficulties.

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Warmly welcome the leaders of Tieling County to visit Shimo Valley Industry Group

Warmly welcome the leaders of Tieling County to visit Shimo Valley Industry Group

May 27,2022

On the morning of May 25, 2022, Sun Zhonghai, deputy head of Tieling County, led a team to visit Graphite Valley Industry Group, accompanied by Executive Deputy General Manager Mei Jia. The two sides had in-depth discussions on the development of Graphite Valley, artificial graphite projects and other topics. As the Tieling County delegation moved to the meeting room, Executive Deputy General Manager Mei Jia introduced the development history, industry overview, and enterprise situation of the Graphite Valley Industry Group, which was highly recognized by the Tieling County delegation. During the negotiation process, the relevant leaders of Tieling County showed great interest in the artificial graphite project, and said that as a leading company rooted in the graphite, graphene and other new carbon material industries, Graphite Valley Industry Group is on the same front as Tieling County. His teammates hope that the two parties can cooperate in depth in the graphite industry in the future and contribute to the development of the graphite industry. After the negotiation, Executive Deputy General Manager Mei Jia led the Tieling County delegation to visit the Graphite (ene) New Materials Research Institute, Graphite Science and Technology Exhibition Hall and Digital Workshop. During the visit, the two sides talked about achievements, innovation and development, and further unified opinions. Mei Jia said that the Graphite Valley Industry Group has entered a period of rapid development and has determined the strategic goal of "one small step a year, one big step in three years, and five years on the platform to build a tens of billions of listed companies. In the future, Graphite Valley Industry Group will build and build a complete ecological blockchain for the graphite (ene) new material industry through industrial layout, technological innovation, and combined with the capital market, promote industry development, create industrial highlands, grasp development opportunities, and adhere to innovation leadership. Determined to become a leader in the new energy and new material industries, to promote the rapid and healthy development of strategic emerging industries and contribute to the sustainable economic and social development. Wang Zhuo, director of Tieling County Project Service Center, Zhao Xueqiang, Secretary of the Party Committee of Shuangjingzi Town, Tieling County, and Gao Fei, deputy mayor of Shuangjingzi Town, Tieling County, participated in the event.

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New process uses CO to produce high-quality graphene at lower cost and faster production

New process uses CO to produce high-quality graphene at lower cost and faster production

May 30,2022

Russian researchers have proposed the first graphene synthesis technology using carbon monoxide as a carbon source. This is a fast and cheap method for producing high-quality graphene. The equipment is relatively simple and can be used in electronic circuits, gas sensors, optics and other fields. The research was conducted by scientists from Skolkovo Science and Technology (Skoltech), Moscow Institute of Physics and Technology (MIPT), Institute of Solid State Physics of the Russian Academy of Sciences, Aalto University and other institutions. The research has been published in the prestigious journal Advanced Science. Chemical vapor deposition (CVD) is the standard technique for synthesizing graphene, which is a honeycomb-arranged single-atom-thick sheet of carbon atoms with unparalleled performance and can be used in electronic applications. CVD generally involves the separation of carbon atoms from gas molecules and their deposition in a monomolecular layer on a substrate in a vacuum chamber. Copper is a commonly used substrate, and the gases used have been hydrocarbons: methane, propane, acetylene, spirits, etc. "The idea of synthesizing graphene from carbon monoxide came up a long time ago, because carbon monoxide is one of the most convenient carbon sources for growing single-walled carbon nanotubes. We have nearly 20 years experience working with carbon monoxide. However, the first experiments with graphene were not successful, and it took us a long time to understand how to control the nucleation and growth of graphene. The beauty of carbon monoxide is the complete catalytic decomposition, which allows us to achieve self-limiting synthesis of single-layer graphene large crystals under ambient pressure." Skoltech Professor Albert Nasibulin, the study's lead researcher, said. "This project is one of the outstanding examples of how basic research can benefit applied technology. As the understanding of the deep-level kinetic mechanism of graphene formation and growth is verified both theoretically and experimentally, optimal conditions for the formation of large graphene crystals become feasible," emphasizes Krasnikov Dmitry, a co-author of the paper and a senior research scientist in Skoltech. The new approach benefits from the so-called self-limiting principle. At high temperatures, when carbon monoxide molecules approach the copper matrix, they tend to decompose into carbon atoms and oxygen atoms. However, once the first layer of crystalline carbon is deposited and separates the gas from the substrate, this tendency subsides, so this process naturally favors the formation of a monolayer. Methane-based CVD can also operate in a self-limiting manner, but to a lesser extent. Grebenko Artem of Skoltech, the first author of the research paper, said, "The system we used has many advantages: the resulting graphene is purer, grows faster and forms better crystals. In addition, by completely excluding hydrogen and other explosive gases from the production process, this improvement can prevent accidents." The fact that this method eliminates the risk of combustion means that no vacuum is required. The equipment works at standard pressure, making it much simpler than traditional CVD equipment. The simplified design in turn leads to faster synthesis. Grebenko said: "From taking a piece of bare copper to pulling out graphene, it only takes 30 minutes." Since the vacuum is no longer required, the equipment not only works faster, but also becomes cheaper. The researchers emphasize that "once you give up the high-end hardware that produces ultra-high vacuum, you can actually assemble our 'garage solvation' for no more than $1000." The researchers also emphasize the high quality of the final material: "Whenever a new graphene synthesis technique is proposed, researchers must prove that it produces the effects they claim. After rigorous testing, we can confidently say that we are indeed high-grade graphene, which can compete with materials produced by CVD from other gases. The resulting material is crystalline, pure, and can be large enough for electronics.

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Graphene modified diaphragm eliminates local temperature hot spots and stabilizes lithium metal anode

Graphene modified diaphragm eliminates local temperature hot spots and stabilizes lithium metal anode

May 30,2022

Lithium-ion battery is an advanced electrochemical energy storage technology for portable electronic devices and electric vehicles. However, the traditional lithium-ion battery with graphite as the negative electrode has a low specific capacity and energy density is close to the limit, which makes it difficult to meet the demand for high energy density secondary batteries. Lithium metal anode is regarded as a very competitive candidate material for achieving high energy density secondary batteries due to its ultra-high theoretical specific energy and lowest electrochemical potential. However, in the actual situation, lithium metal due to its high electrochemical activity and tend to dendrite morphology of uneven deposition characteristics will greatly shorten the service life of the battery, resulting in thermal runaway and other safety issues. Recently, Professor Tang Wei's team from the School of Chemical Engineering of Xi 'an Jiaotong University, Professor Liu Zhaolin from Singapore's A * STAR Institute of Materials Engineering, and Xie Jingying, chief researcher of Shanghai Space Power Research Institute, established a heat transfer-electrochemical deposition coupling model to investigate the space-time evolution of heating power, temperature and lithium ion distribution of lithium deposition system under different deposition currents and overpotentials. The model results show that there are local temperature hot spots at the tips of lithium dendrites, and the existence of local hot spots aggravates the uneven local lithium deposition, which further promotes the growth of lithium dendrites. By introducing graphene sheet coating diaphragm as an in-situ thermal dispersion medium to eliminate local temperature hot spots, the growth of dendrites can be effectively inhibited, and uniform and dense deposition morphology and efficient and stable cycle can be achieved. The composite diaphragm lithium-copper half-cell achieves a stable cycle of 95% coulombic efficiency and more than 240 cycles at a current density of 1 mA cm-2. The lithium metal electrode cycled under the regular PP diaphragm can be "restored" by the composite diaphragm to a stable and efficient cycle with a coulomb efficiency of more than 95% and a more uniform lithium deposition morphology after the cycle coulomb efficiency is reduced to about 60%. In addition, the composite separator achieves stable cycling, high capacity retention and "recovery" characteristics in a Li | | NCM811 battery with a 30.06 mg cm-2 ultra-high load cathode (3.3 low N/P ratio). The article was published in the top international journal Advanced Energy Materials. 1. Simulation of thermodynamic properties of lithium deposition The coupled heat transfer-electrochemical deposition model reveals the local temperature hot spots of the uneven lithium deposition tip under different deposition overpotentials and current densities. The original defects on the surface of the lithium metal electrode lead to non-uniform distribution of the electric field, causing local concentration of lithium ion flux and large reaction current density, resulting in preferential deposition of lithium ions in the tip region and accompanied by ultra-high heat generation rate. The high rate of heat generation and the low thermal conductivity of conventional liquid electrolytes and polymer separators result in significant localized temperature hotspots at the dendrite tips. 2. High thermal conductivity composite diaphragm Excellent single-layer/few-layer graphene dispersion can be obtained by electrochemical exfoliation method and a composite membrane with layered stacked graphene layers covering commercial membranes can be obtained by simple vacuum filtration method. The ion transport characteristics and mechanical strength of the composite separator remain good compared to the original separator, and the wettability and in-plane thermal conductivity are greatly improved. 3. Lithium deposition characteristics and electrochemical performance The structural characteristics of the commercial PP separator and the original defects on the electrode surface cause the lithium deposition to tend to form dendrites and generate local temperature hot spots, which in turn accelerate the aggregation of lithium ions at the tip of the dendrite lithium deposition to further intensify the growth of lithium dendrites. The high thermal conductivity graphene layer on the surface of the composite diaphragm can spread the accumulated heat in time, effectively avoiding the deterioration of dendrites. A large number of irregular dendritic lithium deposits were observed on the surface of the copper current collector after cycling of the blank separator half-cell. In contrast, the composite separator half-cell achieved a relatively uniform deposition morphology. Therefore, the composite separator battery can achieve long cycle stability of more than 240 weeks at a current density of 1 mA cm-2, with a CE of more than 95%. In addition, the lithium metal electrode with degraded performance after cycling under the blank separator can "recover" to better surface morphology and cycling stability under the composite separator. 4. Full battery performance of lithium metal batteries The effectiveness of the high thermal conductivity diaphragm to eliminate local temperature hot spots to suppress lithium dendrites was further verified by the NCM811 full battery. The composite separator not only achieves more stable cycling and capacity retention in regular surface load positive electrode batteries, but also achieves better capacity retention and "recovery" characteristics when matched with an ultra-high surface capacity positive electrode of 30.06 mg cm-2(3.3 low N/P ratio). The evolution of heat generation rate around lithium dendrites and its relationship with local dendrite growth were investigated based on a coupled electrochemical deposition-heat transfer model. Local rapid electrochemical deposition can easily lead to the accumulation of heat and the generation of temperature hot spots, which leads to the subsequent rapid growth of lithium dendrites, which in turn forms a more serious hot spot problem. The introduction of high thermal conductivity graphene layer on the surface of the diaphragm as an in-situ thermal diffusion medium can effectively eliminate the temperature hot spot, resolve the potential risk of rapid deterioration of dendrites, and obtain a more uniform lithium deposition morphology and stable and efficient electrochemical performance. This study provides a unique thermodynamic perspective for the in-depth understanding of the growth and evolution of lithium dendrites, and paves the way for the effective protection of lithium metal anodes and the practical application of lithium metal secondary batteries.

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Strong feelings of rice dumplings warm people's hearts, graphite valley for all employees to distribute Dragon Boat Festival benefits!

Strong feelings of rice dumplings warm people's hearts, graphite valley for all employees to distribute Dragon Boat Festival benefits!

Jun 01,2022

As the Dragon Boat Festival is approaching, in order to thank all employees for their hard work for the company's development, on May 31, Graphite Valley issued Dragon Boat Festival benefits to all employees, making employees deeply feel the care and warmth of the Graphite Valley family. Welfare distribution site, we cooperate with each other, carrying, distribution, distribution...... the scene from time to time bursts of laughter, everywhere is permeated with the atmosphere of joy. Colleagues from various departments went to the scene to collect the zongzi gift box in an orderly manner. Boxes of Duanyang gift boxes full of the company's care and blessings "rushed" to various positions and passed on to every employee. The company was permeated with a warm and harmonious festive atmosphere. A zongzi, a care, zongzi brings not only the enjoyment of taste, but also a good blessing! The joy of the employees who received the welfare was beyond words. They all said that although the zongzi is small and affectionate, it not only allows everyone to feel the festive atmosphere in advance, but also integrates the company's strong care into the wisps of zongzi. Over the years, Graphite Valley has always attached great importance to the humanistic care for employees. Every traditional festival, it will distribute intimate and affordable welfare items to employees, so that employees can share the development achievements of the enterprise, which not only reflects the "people-oriented" corporate culture of Graphite Valley, but also enhances the cohesion of the team, improves the sense of ownership of employees, and adds impetus to the development of the enterprise.

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