Inhibiting Shuttle Effect by Artificial Membranes with High Lithium-ion Content for Enhancing the Stability of Lithium Anode
The low cycle stability of lithium anode has become one of the bottlenecks restricting the development of lithium-metal batteries with high theoretical energy density. Serious side reactions between lithium and electrolyte components are one of the key reasons for the poor cycle stability of lithium anode. Herein, lithiated graphene oxide (GO-Li) and lithium poly(styrene sulfate) (PSS-Li) are used to construct the composite membranes for the protection of Li-anode, which show the long-term operation over 1000 h in Li‖Li symmetric cells in the presence of redox chemicals as an indicator of side reaction source. The high content of Li+ of PSS-Li can not only inhibit the dissolution and diffusion of redox molecules in the membrane, but also improve Li+ transport rate through the membrane. Taking lithium-oxygen (Li-O2) battery as the model device and 2,2,6,6-tetramethyl-1-piperidinyloxy as model redox chemicals to accelerate cathodic reaction. Compared with those of conventional membranes, the artificial membranes can effectively inhibit the side reaction between the redox molecules and lithium anode. Consequently, the energy efficiency and cycle stability (over three times) of Li-O2 batteries are greatly improved. It provides an important theoretical basis and technical support for the design and preparation of membrane for high performance energy-conversion batteries.