Researchers at Penn State University in the United States have developed a new strategy that can expand the application of silicon-based negative electrodes in lithium-ion batteries and increase the power of electric vehicles and smartphones by 20%.
Donghai Wang, a professor of mechanical and chemical engineering, said: "Silicon is expected to become the anode material for the next generation of lithium-ion batteries. However, research shows that this material is very unstable during cycling." In the cycle of traditional lithium-ion batteries, silicon is used as a The negative electrode material will undergo severe volume expansion and contraction, limiting its commercial application potential. This repeated volume change during charging and discharging damages the battery structure. Over time, it will cause unstable phenomena such as explosion of the battery and shorten the battery life.
Researchers have developed new strategies to maintain the elasticity of silicon materials to better transmit energy and maintain electrode integrity. Wang said: "We found that using a superelastic gel polymer electrolyte (GPE) buffer layer, surrounding the silicon-based negative electrode, can keep the silicon stable and prevent the particles in the electrode from moving." The GPE material consists of a soft ether part and a hard cycle part Composition, the soft ether portion provides elasticity, and the hard circulation portion prevents excessive expansion of the polymer. "The two parts work together to properly expand and contract the GPE material while keeping the silicon anode structure stable."
Researchers said that this strategy may solve the current problems faced by silicon-based anodes and increase the energy storage of lithium-ion batteries by 20%. Wang said: "In the past, only 5% silicon was used in the battery, and the effect was very limited. With this method, we can use a pure silicon anode, significantly increase the battery capacity and energy density, and create the next generation of lithium ions. The battery paves the way. "