NIO's announcement of its 150kWh solid-state battery pack instantly shook the market and was immediately interpreted as the arrival of a revolution in battery technology, a devastating blow to traditional power batteries.
But in fact, solid-state batteries have only taken the first step in a long journey, and there are still many mountains to climb.
Liquid batteries and solid batteries
The four main materials of a liquid battery are the positive electrode, the negative electrode, the separator, and the electrolyte.
Solid-state batteries currently come in two forms: all-solid-state batteries and semi-solid-state batteries. NIO's 150kWh solid-state battery pack is the latter.
All-solid-state batteries replace the separator and electrolyte with ceramic-based solid electrolytes (sulfide LiPSCl; oxide LLZTO, LATP). All-solid-state batteries completely eliminate the solvent.
Quasi-solid-state (semi-solid-state) batteries: In all-solid-state batteries, the ceramic-based electrolyte has poor contact with the positive and negative electrodes (solid-solid interface). Quasi-solid-state batteries use polymer-based materials such as PVDF and PEO as solid electrolytes. However, after the polymer-based PVDF and PEO films are formed, they contain residual solvents that cannot be completely removed (such as the previous jelly batteries, which are semi-solid-state). Therefore, they are called semi-solid-state/quasi-solid-state batteries.
According to industry chain research, solid-state batteries will gradually achieve commercialization by 2025 and become the main technology route for power batteries by 2030. Against this backdrop, major countries around the world are heavily investing in this field, primarily in Europe, America, China, Japan, and South Korea, with a total of 53 companies engaged in solid-state battery research and development, of which approximately 9 focus on sulfide solid-state batteries.
1. China
Oxide solid-state batteries are currently quite popular in China, and the level of oxide solid-state batteries is among the world's leading.
Many companies claim to be making solid-state batteries, such as ProLogium (Taiwan), Jiangsu Qingtao, Beijing Weilan, Ganfeng Lithium, CATL, Guoxuan High-Tech, Wuxi Haite, and SAIC. The first four are relatively close to industrialization, having already built at least pilot-scale experimental lines and having products shipped for use in drones, thus beginning commercial applications.
2. Japan and South Korea
Japan has made a very large strategic investment, mobilizing the entire nation and uniting 38 Japanese institutions to promote the industrialization of sulfide-based all-solid-state batteries.
The Japanese Ministry of Science and Technology (low-carbon new energy project, investing 1.5 billion yen annually to support R&D from 2013 to 2022) and the New Energy Research and Development Institute (3 billion yen annually from 2016 to 2022; solid EV project from 2018 to 2022, with an annual investment of 1.8 billion yen in 2018) have jointly invested in three projects. It is expected that the penetration rate of sulfide all-solid-state batteries in the Japanese power battery market will reach 50% and 95% in 2025 and 2030, respectively.
Currently, Toyota, Panasonic, Hitachi, and others have exhibited samples of sulfide-based all-solid-state batteries and announced that mass production of sulfide-based all-solid-state cells will begin in 2025.
There are three main South Korean companies: Hyundai, LG Chem, and Samsung. In March 2020, Samsung published a report in Nature Energy on a sulfide all-solid-state battery that had undergone more than 1,000 cycles at 60 degrees Celsius, using a lithium-free silver-carbon composite anode material. This is currently the best publicly available data on a sulfide all-solid-state battery.
3. Europe and America
In Europe, the main drivers are Germany, France, and the UK, primarily driven by automakers. Examples include Dyson in the UK, and BMW and Volkswagen in Germany.
The U.S. Battery 500 program receives substantial government policy support, encompassing advanced sulfide design, cell design, and more. Notable startups within the program include Quantum Scape, SolidPower, Cymbet, Polyplus, 24M, and Sakti3.
It is clear that the solid-state battery field has entered a stage of fierce competition, with battery companies, car manufacturers, investment institutions, and research institutions vying for dominance in terms of capital, technology, and talent.
