Preparation of PAN-based carbon fiber/Co3O4 composite and potential application in structural lithium-ion battery anodes

Lightweight polyacrylonitrile (PAN)-based carbon fiber can give volume and mass savings, which has been considered as a promising anode material for structural lithium-ion batteries (SLIBs). However, the current issue is the limitation of low capacity. To improve the situation, a novel PAN-based carbon fiber/Co3O4 composite (CF/Co3O4) has been developed through a chemical deposition method. Since combining advantage of high theoretical specific capacity of Co3O4 and great electroconductivity as well as strong mechanical of carbon fiber, the prepared CF/Co3O4 shows excellent performances as an anode material for SLIBs. It presents a coulombic efficiency of over 99% and stable cyclic ability. Even if the number of cycles reaches to 150, a steady discharge reversible capacity up to 625 mAh g(-1) can be retained, approximately 2.7 times as much as pure CF (similar to 230 mAh g(-1)). The improved cycling stability of CF/Co3O4 can be owed to the interactions between CF and Co3O4 anchored on the CF. Furthermore, a solid polymer electrolyte was also prepared with the flexibility, which shows a steady discharge reversible capacity of 500 mAh g(-1) at 100 mA g(-1). The paper provides an affordable method to solve the problem of the limitation of capacity in current SLIBs when using commercial carbon fibers as anode materials.