Hybrid films constructed by carbon nanotubes and carbon nanocoils as current collectors for lithium-ion batteries

Abstract

Lithium-ion batteries (LIBs) have attracted extensive attention in many fields but are still limited in application by capacity loss under long cycles. The poor contact between the current collector (CC) and active materials is one of the reasons that cause the energy attenuation of LIBs during long-term use. Herein, hybrid films constructed by mixing carbon nanotubes (CNTs) and carbon nanocoils (CNCs) through a simple vacuum filtration method are used as CCs for LIBs. It is found that the LIB using the film with a mass ratio of CNTs: CNCs = 3:1 shows the best performance, exhibiting a high capacity of 135.7 mAh g−1 at 5C, and stable cycling performance (>99% capacity retention) after 500 charge/discharge cycles at 1C. The excellent contact of active materials with the CNT-CNC hybrid film is achieved by the well-constructed CNC skeleton, making the CNTs more dispersed to form a uniform and interconnected structure. This work certifies that the CNT-CNC hybrid films are a promising candidate as CCs for high-performance LIBs.