Strategies to Realize Compact Energy Storage for Lithium-Sulfur Batteries

High volume energy density(Ev)means more energy can be stored in a small space,which helps ease the“space anxiety”faced by electrochemical energy storage(EES)devices such as batteries.Lithium-sulfur batteries(LSBs)are promising next-generation EES devices due to their high theoretical energy density.However,its E_(v) is unsatisfactory due to the low density of sulfur and excess use of lightweight nanocarbon in the cathode,severely limiting its practical applications.In this review,the recent progress in improving the E_(v) is summarized from the aspects of materials,electrodes,and devices.First,the key factors affecting E_(v) are discussed.Then at the material level,the design of materials with high density and rich pore structure,and the key roles of catalysts are discussed.At the electrode level,the design of the compact electrode structure is summarized.Increasing the thickness of the cathodes or reducing the use of the anodes(low N/P ratio)to improve E_(v) from the device level is highlighted.Finally,the E_(v) of solid-state LSBs system has been prospected.