Academician Zhang Jiujun: Lithium batteries are facing ten major challenges, safety is the most important factor

ABEC 2020│The 8th Battery \"Davos\" Forum Site

Battery \"Davos\"-Battery Network News on October 27th (Chen Yu Zhang Qian, Changsha Ningxiang live photo and text)On October 27-29, the annual global battery industry event-ABEC 2020 | The 8th China (Changsha·Ningxiang) International Battery New Energy Industry Summit Forum was grandly held in Changsha Ningxiang. This forum is hosted by the ABEC (Battery \"Davos\") Organizing Committee, Zhongguancun New Battery Technology Innovation Alliance, and is exclusively co-organized by Ningxiang High-tech Zone. More than 500 people from the global battery new energy industry chain \"government, industry\" Representatives from all walks of life, including science, education, research, finance, service, and use, as well as the media attended the event. Under the background of global competition in battery new energy, they explored the upward path of independent brands and discussed the construction of the industrial healthy ecological chain.

During the same period of the forum, the 2020 Hunan (Changsha) Battery Industry Expo, sponsored by the Hunan Provincial Department of Industry and Information Technology, Hunan Provincial Department of Commerce, and Changsha Municipal People’s Government, was grandly opened with an exhibition area of ​​20,000 square meters, focusing on cutting-edge industrial products, technologies, and services. Bringing together BYD, BAIC New Energy, Chery New Energy, Lishen Battery, Vision Group, Xinwangda, Electric General, Zhongke Star City, Huabao Energy Storage, Polyfluoride, Shida Shenghua, Jin Yinhe, Han's Laser, Austrian Nearly 200 high-quality exhibitors in the battery new energy industry chain, such as Tewei and Wuxing Aluminum.

Academician of the National Academy of Engineering of Canada / Academician of the Royal Academy of Sciences of Canada / Dean of the Institute of Sustainable Energy of Shanghai University Zhang Jiujun

On the morning of the 27th, Zhang Jiujun, Academician of the National Academy of Engineering of Canada/Academician of the Royal Academy of Sciences of Canada/Dean of the Institute of Sustainable Energy of Shanghai University, made a speech entitled \"Global Development of Electric Vehicle Batteries and Lithium Batteries: Current Status, Challenges and Prospects\" at the forum. The keynote speech shared the development trend of new energy electric vehicles, electrochemical energy technology, lithium battery development trend, etc. The battery network selected some of its wonderful views, in order to enjoy readers:

Zhang Jiujun said that vehicles based on fossil fuels will cause pollution and damage our environment. Transportation by electric vehicles can avoid these problems. The major developed countries in the world have listed the development of new energy vehicles as a national strategy, and electrochemical technology is considered one of the most feasible and effective ways to store and convert clean energy. Lithium-ion batteries have high energy and power density, diverse models and sizes, can freely configure energy according to device requirements, are much lighter than other secondary batteries, have higher open circuit voltage than liquid batteries, have no memory effect, and self-discharge The advantages of low speed and environmental friendliness, but also insufficient battery life, high internal resistance, and safety issues. \"For the further development of lithium-ion batteries, it is necessary to develop new electrode materials, improve cycle life, reduce charging time, and improve safety.\"

Zhang Jiujun also pointed out that in order to achieve a more ideal state of lithium batteries, there are ten challenges: energy density, power density, safety characteristics, cycle life, calendar life, self-discharge, fast charge performance, temperature range, resource environment ,cost. He believes that in the future, improving energy density, power density, and lifespan will still be the research focus of battery development. Energy density is the most concerned indicator of research and development, and is considered a sign of technological upgrading, and exploring low-cost high-performance electrode/electrolyte materials Is the key factor, and safety is the most important factor for future lithium batteries. \"Safety first, the best battery cannot be used without safety.\" He emphasized.

Regarding high-energy density batteries, Zhang Jiujun analyzed that the further development of liquid and solid-state lithium batteries (including lithium-ion batteries, lithium-sulfur batteries and lithium-air batteries) is a necessary strategy to achieve the 500Wh/Kg energy density goal of electric vehicles and can be further explored Li-CO₂The feasibility of batteries and anodeless Li batteries in achieving high energy density targets greater than 500 Wh/Kg.

\"We can see that the energy density of the first generation of lithium batteries is about 100wh/kg, the second generation has been developed to 200wh/kg, and the ternary system is basically in the third generation, about 200-300wh/ kg. \"Introduced by Zhang Jiujun, \"Lithium-sulfur battery has the advantage of high energy density, which can reach 500-600wh/kg. However, the current development has several problems, the cycle life is not very high, due to the shuttle of sulfur Effect, safety is also a big issue.\"

\"Lithium-air battery, its energy density can theoretically reach more than 3000wh/kg, which is equivalent to 10 times the density of the best lithium battery, but its current problem is that its life is not good. The main direction of current development is to develop new Materials, especially on air electrodes. \"On the forum, Zhang Jiujun also proposed an improvement strategy for lithium-air batteries: one is to develop suitable carbon-air electrode materials to increase the cycleability of the system and increase the catalyst loading; the other is to seek excellence The catalyst reduces overvoltage to improve energy efficiency. For example, the development of dual-functional nanocatalysts with obvious catalytic effects on both oxygen reduction reactions and oxygen evolution reactions; third, the development of efficient air filtration membranes for separationO₂,in the airH₂O, CO₂、N₂Other pollutants have a serious destructive effect on the organic system; the fourth is to develop a composite system or a solid-state system lithium-air battery.