Dr. Ji Yajuan from EVE gave a speech at the 2nd International Conference on New Energy Vehicle and Power Battery.

It is a great honor to have the opportunity to share with you the material technology research progress of EVE.

The development of power batteries is inseparable from the drive of policy and technology. At present, based on China's goal of carbon emission peak by 2030 and carbon neutrality by 2060, both the energy supply side and energy demand side will usher in huge changes.

Carbon neutrality strategy sets the tone for new energy development

Based on the market development research on domestic and foreign power battery, we believe that the trend of electrification will come ahead of schedule with the rapid advance of the global electrification and is expected to enter the TWh era in 2023 or even earlier. With such a large demand, how should we choose the power battery technology route?

According to the market research forecast, the LFP battery and NCM battery will coexist for a long time in future. With the advent of blade batteries and CTP technology, the energy density of LFP batteries has been greatly improved. From the perspective of NCM, long-term high specific energy is the development trend while high nickel will become the mainstream.

Strategic layout of power battery provides comprehensive solutions

EVE is one of the few suppliers in the lithium battery industry that has comprehensive solutions for both consumer batteries and power batteries. EVE always insists on being market-oriented and providing customers with comprehensive solutions.

In terms of the production capacity layout of power batteries, we will continue to make a stable layout of the prismatic LFP batteries, prismatic NCM batteries and pouch NCM batteries. For cylindrical batteries, we have also completed the strategic layout of large-sized cylindrical batteries.

Advantages of pouch batteries are highlighted

Under the same chemical system design, the pouch battery structure determines its high specific energy advantage which is at least 5% higher than that of the cylindrical battery. In terms of cycle life, pouch batteries are at least 10% higher than prismatic batteries.In addition, the pouch battery packed with aluminum plastic film has advantages of high security, low internal resistance, high power and flexible size. Customization is also available.Full automation and high consistency are the advantages of our products. We use fully automated equipment and advanced management system，and in terms of quality management, we have always been extremely conscientious to manage the entire chain of dust, screws, burrs, and welding slag.

Technology layout of EVE’s pouch battery

In the BEV market, EVE will realize the upgrading process from 240Wh/Kg to 280Wh/Kg and to 320Wh/Kg. Before 2023, prismatic batteries will be dominant, and we will steadily deploy LFP and NCM material systems. After 2023, we will gradually promote large-sized cylindrical batteries and pouch batteries. In the PHEV market, based on the unique advantages of pouch battery, we will simultaneously promote the application of pouch batteries and prismatic batteries.At present, the 300Wh/kg B sample product has a normal temperature cycle life of 3000th, a high temperature cycle life of 1000th, and can achieve 18min fast charge. The future goal is to achieve 9 minutes.

A major breakthrough in the new safety technology of high nickel materials

When it comes to high specific energy batteries, especially high nickel battery systems, everyone is worried about the safety issues. At present, we have made new safety technology breakthroughs by mainly using another material with higher safety performance.What’s more, the high oxidation activity of the positive electrode during the use of high nickel materials will bring about the continuous oxidation of the electrolyte, which will result in the continuous oxidation and decomposition of the electrolyte. Our technology solves the bottleneck of the continuous growth of DCIR during high-temperature storage.

Cutting-edge technology, continues to break through

In the field of cutting-edge technology research, EVE has been striving to be in the forefront. In the 350Wh/kg platform project research, normal temperature cycle life is expected to reach 400th.

EVE’s research on solid-state battery is gradual. The first generation of products is the research of polymer solid-state batteries, which have initially achieved stable operation at room temperature and will be applied in micro-electronic products. The second generation of products will further develop solid-state interface technology for high-end consumer products. The third generation of products will continue to improve the stability of the interface and ultimately apply in the power battery and energy storage market.

The reserve of traditional lithium-ion battery technology can guarantee our technological leadership in the next 5 years, but we will also think about how to ensure that our technology is still fully advanced in the next 10 years. For lithium-sulfur batteries, we have overcome high-capacity sulfur cathode electrode technology and mastered the core technology of functional electrolytes. In fuel cell research, batch manufacturing technology of independent innovative alkaline ion exchange membrane materials has been realized.

To innovate unceasingly

Strategically, EVE does not make technical choices but we search for the most suitable application market on existing prismatic batteries, pouch batteries and cylindrical batteries. And we develop LiFe and NCM materials to fully match customer needs.

Pouch batteries have safety advantages on cell level, but there’s heat spreading problem on system level. However, this will not affect the subversion of next-generation battery products. It is possible that the large-sized cylindrical battery can solve the heat spreading problem. At the same time, we will develop next-generation solid-state battery technology to fundamentally solve safety issues.

EVE has always attached great importance to the research and development of basic materials and technologies. We will employ a huge investment to do related technical research. In addition, strengthen cooperation with well-known colleges and enterprises at home and abroad so that the scientific research results can better guide us to interpret and apply materials.

We will also actively carry out in-depth cooperation with domestic advanced materials companies. We welcome the suppliers of materials and technology to do such a thing with us.