Abstract: "Solid-state batteries are a stage of card position in the world, and more capital will be invested to choose which can solve the key interface impedance and conductivity problems, or have innovative work on the positive and negative electrodes. Zhang Lei, chief analyst of Caitong Electric New Electric Vehicle, said.
The site of the 2024 Solid-State Battery Industry Ecosystem Entrepreneur Summit
Battery 100 - Battery Network, June 30 (Evergreen Lin Yin, reported from Suzhou, Jiangsu) On June 28, the 2024 Solid-state Battery Industry Ecosystem Entrepreneur Summit, a solid-state battery industry event, was held in Xiangcheng, Suzhou. The forum was hosted by Zhongguancun New Battery Technology Innovation Alliance, Battery 100 Association, and the New Energy Special Committee of Suzhou New Era Business Administration Entrepreneurs Federation.
Zhang Lei, chief analyst of Caitong Electric New Electric Vehicle
On the afternoon of the 28th, Zhang Lei, chief analyst of Caitong Electric New Electric Vehicle, gave a keynote speech entitled "Solid-State Battery - Battle of Card Position" at the forum, sharing the evolution of power battery technology, the core of solid-state battery research and development, solid-state battery material upgrading and challenges, etc., and the battery network excerpted some of its wonderful views for readers:
"The technological development of power batteries can be mainly divided into two routes: high energy and cost-effective, and the iteration of the chemical system is the core of the development of the power battery industry." Zhang Lei said that the development trend of power batteries and the outbreak of new application scenarios such as low-altitude economy have accelerated the development of the solid-state battery industry.
Solid-state battery chemistry upgrade
Zhang Lei introduced that in recent years, the power battery has been continuously innovated and upgraded, with a range of 100 to 1000 kilometers; Energy density from 100 to 300Wh/kg; The cost ranges from 4 to 0.4 RMB/Wh. Facing the future, the three major technology trends of power batteries are higher safety (reducing electrolyte); Smarter (automation and big models); Higher performance (material innovation vs. all-solid-state with a focus on electrolytes).
Solid-state batteries replace flammable organic liquid electrolytes with non-flammable solid-state electrolytes. In addition to conducting lithium ions, solid electrolytes also play the role of separators, and there is room for upgrades such as positive and negative electrode additives.
In terms of safety, solid-state batteries have no risk of combustion and gas production. The traditional electrolyte is easy to react with the positive and negative electrode materials, corrosion, gas production, etc., and the instability temperature of the solid-state battery material is more than 400 degrees (sulfide and ternary cathode); In addition, the battery is hit by external forces and the positive and negative electrodes are short-circuited, which causes instantaneous deflagration and electrolyte leakage.
In terms of energy density, the electrochemical window of solid-state batteries can reach more than 5V, while the electrochemical window of traditional electrolyte systems is generally less than 4.5V.
In terms of life, the liquid electrolyte will interact and react slowly with the electrode material and the encapsulation material, and will dry up, volatilize, and leak over a long period of time. Solid electrolytes can be avoided, which is expected to significantly extend the service life, reduce the overall manufacturing cost of batteries, and lower the technical threshold of battery manufacturing, which is conducive to large-scale popularization.
Zhang Lei mentioned that the core of the early research and development of solid-state batteries lies in solid-state electrolytes. According to the different electrolyte materials, solid-state batteries can be divided into three types of electrolytes: polymer, oxide, and sulfide. Among them, polymer electrolytes belong to organic electrolytes, and oxides and sulfides belong to inorganic ceramic electrolytes. Among them, polymers are easy to process but have low conductivity; Sulfides have the best performance and the highest cost; Oxide cost & performance balance; Halide electrolytes cost less than sulfides and have higher conductivity, but react when in contact with the negative electrode.
In addition, anode materials are the key to short-term energy density improvement, including graphite anode, silicon-based anode, lithium-rich anode, and lithium metal anode.
"The interfacial impedance problem is a key factor affecting the electrochemical performance of solid-state batteries, and good ion contact results can only be achieved at about 6000 atmospheres." Zhang Lei emphasized that at present, all-solid-state batteries are still facing problems such as solid-state interface problems and low ionic conductivity affecting the charge and discharge rate.
Global R&D progress for solid-state batteries
Solid-state batteries are still in the R&D and pilot test stage around the world, and China, Japan and South Korea are in a leading position in the field of solid-state battery development. The industrialization of the next generation of power batteries has been put on the agenda, and in the next few years, the world may accelerate the industrialization process of lithium metal batteries in the form of policy guidance, capital subsidies, and industrial chain coordination.
At present, Toyota's research in the field of solid-state batteries has lasted for nearly 10 years, and its product launch time is expected to be 2026-2028.
South Korea is dominated by sulfide electrolytes in terms of technology paths, and the main companies researching solid-state batteries are Samsung SDI, LG and Hyundai Motor.
In the United States, driven by the Department of Energy (DOE) Science Foundation and national laboratory research, many start-up companies have been born, such as QuantumScape, SEEO, SolidPower, SolidEnergy Systems, IonicMaterials, etc., with polymer electrolytes and oxide electrolytes as the main pathways, and lithium metal as the negative electrode.
At present, Weilan New Energy, Qingtao Energy, Ganfeng Lithium and Taiwan Huineng and other companies have developed semi-solid-state battery samples, all-solid-state batteries are still in laboratory research and development, start-ups are mostly oxides and polymers, and mainstream lithium battery giants are using sulfide routes (CATL, BYD, EVE Lithium Energy).
At present, the development of domestic solid-state batteries mainly includes three stages: the first stage, the introduction of part of the solid-state electrolyte, the reduction of the electrolyte content, the cathode still uses the traditional iron-lithium or ternary cathode; In the second stage, the solid electrolyte content is increased to completely replace the liquid crystalloid solution. In the final stage, the solid-state electrolyte membrane is designed to further increase the energy density.
In addition, in terms of the layout of car companies, domestic companies such as BYD, Weilai, Great Wall, GAC, SAIC, etc. have successively announced their R&D directions, and semi-solid-state batteries have begun to be installed one after another; Japan and South Korea, such as Toyota, Honda, Hyundai, Nissan, etc., have released research and development plans for all-solid-state batteries; Europe and the United States, such as BMW, Volkswagen, General Motors, etc., mainly invest in solid-state batteries, start-up cars, and then introduce car series.
"Solid-state batteries are a stuck stage in the world, and more capital will be invested to choose which can solve the key interface impedance and conductivity problems, or have innovative work on the positive and negative electrodes." Zhang Lei said.
(The above views are based on the shorthand of the forum and have not been reviewed by the speakers themselves.) ）