Long-life lithium-sulfur battery enabled by a multifunctional gallium oxide shield

The practical applications of lithium-sulfur batteries (LSBs) are extremely limited owing to their poor electrochemical performance, which results from the shuttling effect of lithium polysulfides (LPSs) and the growth of Li dendrites. Here, we propose the use of the metal oxide, Ga2O3, which has several types of oxygen vacancies, as a multifunctional shield for ultrastable LSBs. The Ga2O3 shield enhances LPS adsorption by improving the catalytic ability; it also provides stable Li plating and stripping by suppressing Li dendrite growth. The multifunctional shielding of the LSB by the Ga2O3 interlayer results in outstanding ultrastable cycling performance, where the capacity decay was only 0.010% over 4,000 cycles at a high rate of 2C. The proposed multifunctional shield is expected to have a wide range of applications in energy storage systems in addition to LSBs.