Ideals Shine Into Reality: All-Solid-State Batteries Will Be Mass-Produced

Against the backdrop of global energy transformation, new energy technologies are developing rapidly. All-solid-state batteries, as a highly promising next-generation battery technology, are gradually becoming the focus of the industry. Recently, automakers such as Changan Automobile and BYD have announced the installation schedule of all-solid-state batteries, indicating that the commercialization process of all-solid-state batteries is accelerating.

All-solid-state batteries refer to lithium-ion batteries that use solid-state electrolytes. In terms of working principles, they are no different from traditional lithium batteries, but their core, solid-state electrolytes, give them many advantages over traditional liquid lithium batteries.

In terms of safety performance, the electrolyte of traditional liquid lithium batteries is flammable and volatile, which is an important cause of electric vehicle fires and even explosions. The solid electrolyte used in all-solid-state batteries is not flammable, which greatly reduces the risk of battery combustion and explosion, and greatly improves safety. For example, some solid-state batteries can withstand high temperatures of 1,000 degrees and can continue to supply power even if a corner is cut.

In terms of energy density, all-solid-state batteries have obvious advantages. The energy density of traditional lithium batteries has gradually approached a bottleneck. The energy density of lithium iron phosphate batteries is 150-210 Wh/kg, and the upper limit of ternary lithium batteries is about 350Wh/kg. The energy density of all-solid-state batteries is expected to reach more than 500Wh/kg. For example, the energy density of the Jinzhongzhao all-solid-state battery developed by Changan Automobile can reach 400wh/kg, and the cruising range exceeds 1,500 kilometers when fully charged, which greatly alleviates the range anxiety. At the same time, solid electrolytes can withstand higher voltages, and the battery volume can be further reduced, which greatly improves the charging speed, and it is expected to achieve a cruising range of 1,000 kilometers after charging for 10 minutes.

In terms of cycle stability and high and low temperature performance, all-solid-state batteries also perform well. Its cycle life can reach more than 10,000 times, which is much higher than ternary lithium batteries and lithium iron phosphate batteries, and it can maintain good performance in high and low temperature environments, effectively solving the problem of slow charging and fast power loss of traditional lithium batteries in low temperatures in winter.

At present, there are three mainstream technical routes for solid-state batteries: polymers, oxides and sulfides.

Polymer electrolytes belong to the category of organic electrolytes. They are flexible, have good mechanical properties, are easy to process and form, are highly compatible with existing liquid electrolyte production processes, are easy to prepare thin films on a large scale, and have achieved small-scale mass production. However, their conductivity is low at room temperature, usually between 10⁻⁷ and 10⁻⁴S/cm, and they need to be heated to above 60°C to work properly. They have a narrow electrochemical window and relatively poor thermal stability.

Oxide electrolytes are stable in air, have excellent thermal stability, can withstand high temperatures above 600°C, have high mechanical strength, can effectively inhibit the growth of lithium dendrites, and are suitable for high-voltage positive electrode materials such as high-nickel ternary materials. The R&D cost and difficulty are relatively low. However, it also has the problem of low ionic conductivity. The conductivity at room temperature is generally between 10⁻⁶ and 10⁻³S/cm, which needs to be improved by high-temperature sintering or adding liquid electrolytes, and the interface impedance with the electrode is high, resulting in a short cycle life.

Sulfide electrolytes have excellent performance and the highest ionic conductivity. The conductivity at room temperature can reach 10⁻²S/cm, which is close to the level of liquid electrolytes. They support fast charging and discharging, and the theoretical energy density exceeds 500Wh/kg. They are compatible with lithium metal negative electrodes, have good thermal stability, are soft in texture, and have strong plasticity. However, they have poor chemical stability and are easy to react with moisture and oxygen in the air to generate toxic hydrogen sulfide gas. They are difficult to prepare and have high production costs.

Globally, many companies have invested in the research and development and production of all-solid-state batteries and accelerated their layout. Japanese automakers started early in the research and development of solid-state batteries.
Toyota Motors started solid-state battery research and development as early as 2006, and recently announced that it will start small-scale trial production in 2026 and mass production after 2030;
Honda Motors announced that it will start trial production of all-solid-state batteries for pure electric vehicles in January 2025; Nissan plans to start trial production of solid-state batteries at its Yokohama plant this year, and launch electric vehicles equipped with all-solid-state batteries by 2028.

Chinese companies are also unwilling to lag behind. CATL has built a pilot production line for all-solid-state batteries and is currently conducting process optimization and product verification. It is expected to mass-produce all-solid-state batteries on a small scale in 2027.

BYD began research and development of all-solid-state batteries in 2013 and has started feasibility verification of solid-state battery industrialization, covering key material technology breakthroughs, battery cell system development and production line construction. It is expected to start mass demonstration and installation of all-solid-state batteries in 2027 and achieve large-scale commercialization after 2030.

Changan Automobile plans to launch 8 self-developed battery cells, including liquid, semi-solid and solid, by 2030, to launch functional prototypes in 2025, and to gradually mass-produce all-solid-state batteries in 2027.

GAC Aion announced that it will achieve mass production and installation of all-solid-state batteries in 2026, and will first be installed in its high-end brand Haobo;

Chery Automobile plans to achieve all-solid-state battery installation in 2026 and large-scale mass production in 2027;

SAIC Group announced that all-solid-state batteries will be mass-produced and delivered in 2026, and Zhiji new cars equipped with all-solid-state batteries will be mass-produced and delivered in 2027.

From the overall industry perspective, the solid-state battery industry chain is similar to that of liquid batteries, covering upstream raw material supply, midstream battery materials and manufacturing, and downstream application areas. The upstream mainly provides metal resources such as lithium, cobalt, and nickel, as well as core materials for solid-state electrolytes. It has strong resource dependence, high technical barriers, and high market concentration. The midstream is the core link of battery research and development and manufacturing. Technological innovation is the key driving force, but it faces problems of complex processes and high cost pressure. The downstream application fields are wide, covering new energy vehicles, energy storage, consumer electronics and other fields, with strong policy support and huge market potential.

Although all-solid-state batteries have broad prospects, they still face many challenges on the road to commercial mass production.

On the technical level, although some progress has been made in solid electrolytes, positive and negative electrode materials, etc., there are still some basic scientific problems and engineering technical problems that need to be solved urgently. For example, how to further improve the ionic conductivity of solid electrolytes, improve their compatibility with lithium metal and high specific energy electrode materials, and build a compatible and stable solid-solid interface. Different technical routes also have their own shortcomings, such as the poor chemical stability and difficulty of preparation of sulfide electrolytes, and the low ionic conductivity of oxide electrolytes. These problems require continuous R&D investment to overcome.

Cost is also an important factor limiting the large-scale application of all-solid-state batteries. At present, the cost of liquid lithium-ion battery monomers is about 0.5 yuan per watt-hour, while the material cost of solid-state batteries is more than 2 yuan per watt-hour without large-scale mass production. The material cost of a 100-kilowatt-hour battery pack alone exceeds 200,000 yuan, which is much higher than the existing liquid batteries. Taking sulfide solid-state batteries as an example, the rare metal indium required for its production is expensive, and the preparation of lithium sulfide precursors is difficult and costly, which leads to the high overall cost of batteries.

At the market level, solid-state batteries, as new products, need a certain amount of time to gain market recognition and acceptance. Although they have advantages in energy density and safety, there is still room for improvement compared with traditional lithium batteries in terms of cycle life. In addition, although some companies have achieved small-batch sample delivery, they have not yet formed stable orders, and there is uncertainty in the actual application prospects.

Looking to the future, all-solid-state batteries are expected to play an important role in many fields. In the field of new energy vehicles, it will significantly improve the vehicle's cruising range, safety and charging speed, promote the new energy vehicle industry to a higher level, and accelerate the electrification transformation of the automotive industry.

In the field of energy storage, the high energy density and long cycle life characteristics of all-solid-state batteries enable them to store electricity more efficiently, balance electricity supply and demand, and provide strong support for the large-scale access and stable operation of renewable energy.

In the field of consumer electronics, all-solid-state batteries can make devices thinner and more durable, and improve user experience.

With the continuous advancement of technology and the development of the industry, the performance of all-solid-state batteries will continue to improve, and the cost is expected to gradually decrease. The continuous investment and R&D of many companies, as well as the promotion of collaborative innovation between industry, academia and research, will accelerate the technological breakthrough and commercialization of all-solid-state batteries. At the policy level, governments of various countries are constantly increasing their support for new energy technologies, which will also create a good policy environment for the development of the all-solid-state battery industry.

As the key commanding heights of the competition for next-generation battery technology, all-solid-state batteries face multiple challenges such as technology, cost and market, but they have a bright future. In the wave of global energy transformation and technological progress, all-solid-state batteries are expected to become the core force to promote energy storage transformation and usher in a new era of energy storage.