How far is the all-solid lithium battery from high commercialization? Recently, Liu Wei, an assistant professor at Shanghai University of Science and Technology, and Cui Wei, a professor at Stanford University, published an article in the journal "Chemistry" of Cell Press to sort out the development of all-solid lithium metal batteries in recent years and summarize several improvements in the conductivity of solid electrolytes and the latest ways to reduce the high impedance of the interface, the solid electrolytes for the study of embedded compounds, sulfur and oxygen cathode materials, as well as the key challenges and future development of all-solid lithium metal batteries.
As a widely used energy storage device, lithium ion battery has the characteristics of high energy density, good cycle stability and light weight. However, it still cannot fully meet the high energy density requirements of electric vehicles and smart grids. If an all-solid lithium metal battery using a solid electrolyte and a lithium metal negative electrode is used, it is expected to solve problems such as energy density and safety.
However, the solid electrolyte itself has a low electrical conductivity, and the electrochemical instability and incompatibility with the electrode lead to a large interface impedance between the electrolyte and the electrode, which restricts the commercialization process. Liu Wei said at present higher interface resistance is the main reason for restricting the commercialization of all-solid lithium batteries. The way to reduce the interface resistance includes adding a buffer layer and an artificial passivation layer, and mixing solid electrolyte materials in the electrodes. The commercial use of all-solid lithium batteries is still to be studied, but the future is expected.
The article also discusses the latest all-solid lithium metal batteries using embedded compounds, positive electrodes such as sulfur and oxygen. The use of a solid electrolyte instead of an electrolyte can solve problems such as polysulfide dissolution and openness of a lithium-ion battery. It can greatly increase energy density, and is expected to be used in next-generation high-energy energy storage devices.