Nanodiamond‐Assisted High Performance Lithium and Sodium Ions Co‐Storage

Abstract

While lithium resources are scarce for high energy‐dense lithium‐ion batteries (LIBs), sodium‐ion batteries (SIBs), serving as an alternative, inherently suffer from low capacity and the high‐cost use of non‐graphite anodes. Combining Li‐ and Na‐ions within a single battery system is expected to mitigate the shortcomings of both systems while leveraging their respective advantages. In this study, we developed and assembled a nanodiamonds (NDs)‐assisted co‐Li/Na‐ion battery (ND–LSIB). This innovative battery system comprised a commercial graphite anode, an ND‐modified polypropylene (DPP) separator, a hybrid lithium/sodium‐based electrolyte, and a cathode. It is theoretically and experimentally demonstrated that the ND/Li co‐insertion can serve as an ion‐drill opening graphite layers and reconstructing graphite anodes into few‐layered graphene with expanding interlayer space, achieving highly efficient Li/Na storage and the theoretical maximum of LiC6 for Li storage in graphite. In addition, ND is helpful for creating a LiF‐/NaF‐rich hybrid solid electrolyte interface with improved ionic mobility, mechanical strength, and reversibility. Consequently, ND–LSIBs have higher specific capacities ~1.4 times the theoretical value of LIBs and show long‐term cycling stability. This study proposes and realizes the concept of Li/Na co‐storage in one ion battery with compatible high‐performance, cost‐effectiveness, and industrial prospects.