In-situ Sacrificial Positive Additive Strategy for the Construction of a Stable Negative Interface in Dual Graphite Batteries

Due to their merits of affordability, safety, and environmental friendliness, dual graphite batteries (DGBs) have drawn widespread interest as novel energy storage devices. Nevertheless, the development of DGBs is plagued by inferior cyclic stability that arise from the irreversible loss of cations and the anion-cation crosstalk during the formation of an negative interface. We proposed an in-situ sacrificial positive additive strategy to enhance the electrochemical performances, based on the decomposability of potassium oxalate monohydrate (K2C2O4 center dot H2O). The experimental and computational results show that the positive additive can add cations to support a stable negative interface and suppress the anion-cation crosstalk. The as-constructed DGBs with K2C2O4 center dot H2O deliver high-rate capability (31.8 mAh g(-1) at 3.0 C) and excellent cyclic stability (similar to 84.1% capacity retention after 180 cycles). This work provides a new opportunity of negative interface construction for propelling the commercial evolution of the advanced DGBs.