The development of solid-state batteries is a history of technological progress full of innovation and breakthroughs. From the early concept of the proposed, to the gradual attack on key technologies, and then gradually towards commercial application, solid-state batteries have their unique advantages, leading to a new round of changes in battery technology.
The origin of solid-state batteries can be traced back to the 19th century. 1831-1834, the British scientist Michael Faraday (Michael Faraday) discovered the solid electrolytes silver sulfide and lead fluoride; this discovery laid the foundation for solid-state ionics, but also opened the door to the exploration of solid-state battery technology. 1831-1834, the British scientist Joseph Thomson (Joseph Thomson) foresightedly proposed the concept of solid-state batteries. Thomson) prospectively proposed the use of a solid electrolyte instead of a liquid electrolyte to realize the idea of a more stable and reliable battery cycle. However, due to the limitations of materials science and processing technology at that time, this idea could not be rapidly transformed into practical applications, but it pointed out the direction for the development of solid-state battery technology.
In the middle of the 20th century, with the deepening of solid-state physics and inorganic chemistry, all-solid-state battery technology began to receive attention from the scientific research community. In 1969, Liang et al. reported for the first time a thin-film type all-solid-state lithium-ion battery, using LiI as the electrolyte. Soon after, LiI-based all-solid-state thin-film batteries were commercialized and successfully used in pacemakers. However, at that time, the battery was a primary battery, which could not be recharged and had a low absolute capacity, limiting its wide application. In 1983, Toshiba Corporation of Japan developed a practical secondary thin film battery, Li/Li3.6Si0.6P0.4O4/TiS2, which pushed forward the development of solid-state batteries to a certain extent. In 1992, Bates et al. of Oak Ridge National Laboratory of the United States successfully developed an inorganic solid-state thin-film electrolyte, Li/Li3.6Si0.6P0.4O4/TiS2. In 1992, Bates et al. of Oak Ridge Laboratory in the United States successfully developed an inorganic solid-state thin film electrolyte LiPON, and introduced a variety of thin film lithium battery anode and cathode systems, such as Li/LiPON/LiCoO2, etc., which showed excellent cycling performance (10,000 times), and commercialized thin film lithium batteries launched in cooperation with ITN, which has further promoted the research of all-solid-state thin film lithium batteries. However, thin-film all-solid-state batteries for the large-scale application of solid-state lithium batteries are far from enough; the development of high-efficiency, large-capacity body batteries becomes an urgent need.
Into the 21st century, with the rapid expansion of the electric vehicle market and the growing demand for high security, high energy density batteries, solid-state battery technology research has ushered in an unprecedented opportunity for development. Researchers have made significant progress in the fields of electrolyte materials, electrode materials, and interface engineering.
In terms of electrolyte materials, they are mainly divided into three systems: oxide, sulfide, and polymer. Oxide electrolytes mainly include crystalline NaSICON type, chalcocite type, garnet type, and so on. For example, Na1+xZr2SixP3-xO12 (0≤x≤3) was synthesized as early as 1976, and is the earliest known NASICON type I electrolyte. In 2010, Kumar’s group at the University of Dayton Research Institute (U.S.) first reported an all-solid-state lithium-air battery prototype. In 2010, Kumar’s group at the University of Dayton Research Institute reported the prototype of an all-solid-state lithium-air battery that utilized a glass-ceramic material of the NASICON structure as the electrolyte. Chalcogenide-based electrolytes have been studied since 2005, but overall battery performance is low due to the low total conductivity of the electrolyte. Research on all-solid-state lithium batteries based on garnet-structured solid-state electrolytes began in 2010, and after continuous improvement, in 2016, some scholars made all-solid-state batteries based on high-conductivity garnet-structured electrolytes, which can still obtain a high capacity despite the increase in electrode thickness. The oxide solid-state electrolyte route is the technology route with the largest number of companies participating in solid-state batteries in the world by 2023.
In terms of sulfide solid electrolyte, Japan’s Toyota is a leading company on a global scale, and has been developing solid-state batteries since the 1990s, and launched sulfide solid-state batteries in 2010, with a sample battery energy density of 400 Wh/kg in 2014, and its all-solid-state batteries loaded in 2020 with test runs on test roads, with plans to launch the first all-solid-state battery-equipped hybrid vehicle in 2025. It plans to launch the first hybrid model equipped with all-solid-state batteries in 2025. In addition, Panasonic, Samsung, LG Chem, Solid Power, etc. have all chosen the sulfide solid-state electrolyte route. For example, Solid Power adopts ternary cathode materials, lithium-rich anode materials with high silicon content, and its own intellectual property rights of sulfide solid-state electrolytes to produce all-solid-state batteries with an energy density of up to 390 watt-hours per kilogram and a battery life of more than 1,000 cycles.
In terms of polymer solid-state electrolytes, France’s Bolloré Group is an early starter, offering car-sharing services in Paris and its suburbs in 2011 with its self-developed electric cars and buses, which use polymer thin-film electrolytes in their solid-state batteries. Some of the leading companies are focusing on adding the right amount of liquid components to the polymer electrolyte to form a gel structure to improve the ionic conductivity and energy density of the electrolyte.
In recent years, the industrialization of solid-state batteries has been accelerating. In April 2024, Chongqing TaiLan New Energy Company successfully researched, developed and manufactured the world’s first all-solid-state lithium metal batteries compliant with automotive standards, with a single capacity of 120Ah and an energy density of up to 720Wh/Kg, which set a new global record. in october 2024, the first all-solid-state lithium battery mass-produced in china was invested in by Beijing PureLithium New Energy Science & Technology Co. In October 2024, Beijing Pure Lithium New Energy Technology Company invested in the construction of China’s first all-solid-state lithium battery mass production line officially put into production. Numerous automobile enterprises have also laid out solid-state lithium batteries, including BMW Group and Solid Power, to start the joint research and development of all-solid-state batteries, and use the pilot production line provided by the company to promote mass production.
From the conception of the solid-state battery to the milestones achieved today, it is inseparable from the unremitting efforts of researchers and enterprises around the world. As the technology continues to mature and the cost is gradually reduced, solid-state batteries are expected to occupy an important position in the future energy market, bringing new development opportunities for electric vehicles, energy storage, and other fields, and driving the energy industry to new heights.
