CoSnO3 Nanocubes Wrapped by Carbon Nanofibers for Improving Lithium-Sulfur Battery Performances

摘要

To solve the problem of low conductivity of sulfur and "shuttle effect" of lithium polysulfides, CoSnO3 nanocubes wrapped by carbon nanofibers (CoSnO3@CNFs) are synthesized by co-precipitation, electrospinning and calcination techniques. CoSnO3 provides plentiful polar active sites, which restrains the dissolution of polysulfides with chemical interaction. Carbon nanofibers not only provide more ion transport channels, but also increase physical adsorption, provide active sites, and improve the conductivity of the electrode material. As a result, CoSnO3@CNFs can carry about 60 % sulfur as guest. Evaluated as cathode material for lithium-sulfur batteries, CoSnO3@CNFs/S displayed an initial discharge capacity of 554.9 mA h g(-1) at 0.2 C, and retained 300.0 mA h g(-1) after 200 cycles. The simple synthesis method, high sulfur loading capacity and long cycle life make CoSnO3@CNFs extremely attractive for practical applications.