Due to its performance advantages in energy density, safety, low temperature, etc., solid-state batteries are regarded as the next generation of power batteries and are the strategic high ground for competition among various countries.

Dr. Ma Hongyun, director of Lishen Battery Basic R&D Department, delivered a keynote speech on "Research on High Specific Energy and High Safety Solid-State Battery Technology".

Solid-state batteries have great promise

According to my country's "14th Five-Year Plan" power battery technology roadmap, the goals of high energy density batteries in 2025, 2030 and 2035 will reach 350, 400 and 500Wh/kg respectively, which is difficult to meet with traditional liquid batteries.

At the same time, thermal safety accidents of lithium batteries currently occur from time to time, and accident scenarios occur all over the fields of consumption, power and energy storage, causing immeasurable economic losses and casualties, and having a great social impact.

Safety and battery life are also important considerations for consumers when purchasing new energy vehicles.

Therefore, Dr. Ma Hongyun said that it is necessary to develop batteries with both high energy density and high safety.

Solid-state batteries not only have the advantages of high safety and high energy density, but also have excellent "high and low temperature" performance, which can solve the two core concerns of safety and mileage at the same time.

Dr. Ma Hongyun said that from a safety perspective, given a solid-state battery and a liquid-state battery with the same positive and negative electrodes and only a difference in electrolyte, the solid electrolyte has a higher ignition point and its thermal stability is much better than that of the electrolyte. Some solid electrolytes even It is a relatively complete oxidation product (LLZO, LATP, etc.). At the same time, the solid electrolyte has better mechanical properties that can inhibit the formation of lithium dendrites, which makes the intrinsic safety of some solid-state batteries higher than that of liquid batteries.

From the perspective of energy density, some solid-state electrolytes have a wider electrochemical window than conventional electrolytes, which is beneficial to increasing the operating voltage of the battery. Therefore, solid-state batteries may be compatible with more oxidizing cathodes (high nickel/ High-voltage ternary positive electrode, 5V positive electrode), stronger reducing negative electrode (lithium-containing negative electrode). Its non-flow characteristics can realize internal series connection of batteries, simplify battery group design, and help improve battery energy density.

Based on this, the development of solid-state batteries is expected to improve battery energy density while solving safety issues.

New generation semi-solid battery energy density reaches 402Wh/kg

Dr. Ma Hongyun said that after more than 25 years of development, Lishen Battery has established an industry-leading R&D system and formed market-competitive innovation capabilities. It has drafted a total of 10 national standards for the battery industry and has national, provincial and ministerial-level R&D innovation platforms. , and achieved numerous scientific and technological achievements.

Adhering to the concept of "R&D for one generation, reserve for one generation, and apply for one generation", in order to seize the technological commanding heights and development opportunities, Lishen Battery is deeply involved in the research and development of solid-state battery technology. At present, Lishen's semi-solid battery system development work has achieved remarkable results in terms of energy density improvement and safety improvement.

By adopting nano-scale new material surface modification high-nickel cathode technology, multi-element composite silicon anode technology, multi-dimensional electronic and ion superconducting network technology, high safety and high electrochemical reactivity solid-state battery coupling technology, the energy density of soft-pack batteries reaches 360Wh/kg. , can pass 180℃ hot box test and 2 times voltage overcharge, achieving both high energy density and high safety performance.

At the same time, Lishen Battery is carrying out in-depth cooperation with universities and scientific research institutes, using cutting-edge key material technology, breakthrough electrochemical system design, new battery structure design and advanced battery process technology to conquer the 380-400Wh/kg semi-solid battery system.

In January this year, lishen battery completed the development of a new generation of ultra-lightweight and high-safety semi-solid-state batteries with an energy density of 402Wh/kg. It has reached the technological leadership level among similar products in the industry and will be widely used in ultra-long-range passenger cars. , eVTOL and other fields.