Porous polyetherimide membranes with tunable morphology for lithium-ion battery

Polyetherimide (PEI) porous membranes with tunable morphology are constructed via a typical phase inversion method and applied in lithium-ion batteries (LIBs). The morphology of PEI membranes is adjusted by introducing hydrophilic additives, polyvinyl pyrrolidone (PVP), in the cast solution. The obtained PEI porous membranes show typical sponge-like microstructure and more connected and bigger pores are formed in the membranes with the increase amount of PVP. Under LIBs test condition, batteries with PEI membranes show superior thermal stability, good electrolyte wettability , and tunable ion conductivity and rate performance. As a result, a battery with a PEI-2 membrane exhibited comparable electrochemical performance to that of commercial separators. A 96.4% capacity retention rate was obtained after cycling for 100 cycles for a battery with a PEI-2 membrane. Thus, the membranes with controlled performance in LIBs can be realized via adjusting their morphologies. This paper provides an effective way to optimize fabrication parameters of porous membranes for LIBs application.