Performance And Application of Solid State Battery

Solid-state batteries have the potential for technological disruption: the traditional liquid battery system is mature, but it is difficult to make a large performance breakthrough. From the consideration of both high energy density and intrinsic safety, with lithium metal as a negative electrode, the use of stable, non-combustible solid electrolyte all-solid lithium-ion batteries will become the most potential for technological disruption in the future. The possibility of bipolar stacking, the use of lithium metal anode to ensure that it has a large lead in energy density, its energy density can easily exceed 400Wh/kg, solid electrolyte can guarantee excellent safety performance.

Solid electrolyte is the key to the successful application of solid state batteries: the ideal solid electrolyte should have a negligible electronic conductivity, excellent Li+ conductivity, good chemical compatibility, a wide electrochemical stability window, excellent thermal stability, and can be mass-produced at a low cost. Generally speaking, representative solid electrolytes include sulfide solid electrolytes, oxide solid electrolytes, metal halide solid electrolytes and polymer solid electrolytes.

Solid electrolytes have their own characteristics, and composite solid electrolytes can complement each other, which is the most potential direction for development: polymer electrolytes have good interface compatibility and machinability, but the ionic conductivity at room temperature is low, limiting its application temperature; The conductivity of inorganic oxide electrolyte is high, but there are problems of rigid interface contact and serious side reactions, and it is difficult to process. Sulfide electrolyte has high conductivity, but poor chemical stability and poor processability. To solve these problems, the composite solid electrolyte is the most promising system. On the one hand, inert inorganic nanoparticles can be introduced into the polymer electrolyte to improve the performance of the polymer electrolyte. On the other hand, it is possible to combine oxide ceramics or sulfides with polymers to achieve complementary advantages. The composite solid electrolyte has higher ionic conductivity and mechanical properties, and better compatibility with electrodes.

Ion transport mechanism, lithium dendrite growth mechanism, solid-solid interface problems are the three major problems faced by solid-state batteries: Clarifying the realization conditions of high ion conductivity is the key to developing high-performance solid electrolytes and improving the charging and discharging speed of all-solid state batteries. At present, the ion conductivity is mainly improved by doping, developing nanoscale structures and interface engineering. However, the industry's understanding of the ion transport mechanism is not enough, which is a challenge to improve the charging and discharging speed. In addition, although the solid electrolyte has high mechanical strength, it is still difficult to completely inhibit the growth of lithium dendrites and achieve uniform deposition of lithium metal, lithium metal may form dendrites on the negative surface, and even nucleate inside the solid electrolyte, resulting in short circuit of the battery, resulting in safety risks, which is a greater challenge to the safety of solid-state batteries. At the same time, due to the lack of electrolyte infiltration, solid-solid interface problems directly affect the solid-state battery cycle life and other performance, although there are some improvement measures in the process and material dimensions, but the interface problem is still the biggest challenge for solid-state batteries.

All-solid-state batteries are expected to begin mass production and loading in 2027: Since 2022, the research and development and industrialization of solid-state batteries have made obvious progress, especially the semi-solid-state batteries of Chinese enterprises represented by Wei LAN New energy and Ganfeng lithium battery are mass-produced and loaded, marking that semi-solid-state batteries have achieved industrialization. We expect the mass production and loading of solid-state batteries to begin arriving around 2027.

2030 solid state battery market size of more than 250 billion yuan: it is expected that by 2030 the global solid state battery shipments will reach 614.1GWh, the penetration rate in the overall lithium battery is expected to be about 10%, its market size will exceed 250 billion yuan, the main shipped battery is still semi-solid battery. As the most important component of solid-state batteries, the demand for solid-state electrolytes will exceed 60,000 tons in 2030, and the market size will exceed 6 billion yuan.