Band engineering enhances the electrochemical properties by constructing TiO₂ NRs-MoS₂ NSFs flexible electrode

Research and development of flexible electrodes with high performance are crucial to largely determine the performance of flexible lithium-ion batteries (FLIBs) to a large extent. In this work, a flexible anode (TiO₂ NRs-MoS₂ NSFs/CC) is rationally designed and successfully constructed, in which TiO₂ nanorods arrays (NRs) vertically grown on CC as a supporting backbone for MoS₂ nanosheets flowers (NSFs) to form a TiO₂ NRs-MoS₂ NSFs heterostructure. The backbone can not only serve as a mechanical support MoS₂ and improve its electronic conductivity, but also limit the dissolution of polysulfides issue during cycling. The density functional theory (DFT) analysis manifests that the obvious interaction between O and S at the interface for the TiO₂ NRs-MoS₂ NSFs heterostructure changes the electronic structure and reduces the band gap of TiO₂ NRs-MoS₂ NSFs. The small band gap and high electron state at the Fermi level are both beneficial to the transport of electrons, enhancing the kinetics, and giving the long cycling stability at high density and excellent rate capacity. Furthermore, the assembled TiO₂ NRs-MoS₂ NSFs/CC//NCM622 full cell delivers superior rate capacity and good cycling stability. Meanwhile, the soft-packed cell shows good mechanical flexibility, which can be lighted up successfully and keep brightness when folding with different angles. This result illustrates that it is a highly potential strategy for constructing flexible electrodes with the controlled electronic structure through band engineering to not only improve the electrochemical performance, but also possibly meet the requirements of high-performance FLIBs.