From Dual-Ion to Single-Graphite Batteries, a Minimalistic Challenge

Dual-ion batteries (DIBs) are advantageous in the terms of high working voltage, low cost, and environmental friendliness but are short of energy density. In this study, the anode material was saved in constructing the cell with a single graphite cathode which was only countered by a copper current collector. This type of anode-free DIBs was titled as single-graphite batteries (SGBs), which elevated the energy density remarkably. However, they always suffered from a very limited cycle life. By the synergistic addition of both lithium difluoro(oxalate)borate and fluoroethylene carbonate into the electrolyte solution of lithium hexafluorophosphate dissolved in ethyl methyl carbonate, the SGB achieved an impressive cycling stability with 85% capacity retention after 100 cycles. The respective roles played by both additives in the SGB were investigated in detail. This strategy may be useful for the practical application of SGBs.