Feb 18, 2025
What is the problem with solid-state batteries?
What are solid-state batteries? Solid-state batteries are a type of battery that uses solid electrolytes to replace traditional liquid or gel-type electrolytes. Compared to conventional lithium-ion batteries, solid-state batteries have a more stable structure, offering higher energy density, safer performance, and faster charging speed. The main problems with solid-state batteries: Technical Aspects Low ionic conductivity: The strong interaction between ions and high migration energy barriers in solid electrolytes result in lower ionic conductivity compared to liquid electrolytes, leading to slow charging and discharging rates and rapid capacity fading. Lithium dendrite growth: Even with solid electrolytes of high mechanical strength, it is difficult to completely inhibit the growth of lithium dendrites, which can form on the surface of the negative electrode and even penetrate through the solid electrolyte, causing battery short circuits. Solid-solid interface issues: The solid-solid interface in solid-state batteries has a small contact area, and volume changes during electrode charging and discharging can disrupt the interface structure, worsening contact, increasing interface impedance, and potentially causing chemical reactions to form unstable interface layers. Mechanical performance challenges: Solid materials in solid-state batteries are more prone to cracking when subjected to mechanical stress, such as during battery assembly or during vibrations or collisions in use, affecting battery performance and safety. Poor low-temperature performance: Solid-state batteries may experience more pronounced performance degradation in low-temperature environments, affecting their use in cold regions. Cost Aspects High material costs: Expensive materials such as lithium metal and special ceramic electrolytes, including high-priced lithium sulfide, are typically used, resulting in costs significantly higher than those of liquid lithium batteries. High manufacturing costs: The production process is complex, requiring precision processes and equipment, such as high-density stacking and high-precision electrolyte coating, as well as special production environments, with low production efficiency, leading to higher manufacturing costs. Environmental and Recycling Aspects Resource and energy consumption issues: From raw material extraction, processing, to manufacturing, significant natural resources and energy are consumed. The mining and refining of new materials can damage the environment, and the high energy consumption during production increases carbon emissions. Recycling challenges: The recycling and disposal of discarded solid-state batteries pose challenges. Their internal structures are complex, containing multiple metals and chemicals. Improper recycling can pollute the environment, and recycling technologies and processes are immature and costly.