Regulation of dual-ion batteries via the defects design in carbon electrode based on the different storage behaviors of PF6- and Li+

Dual-ion batteries (DIBs) have aroused much attention due to their high energy density, low cost, and environmental friendliness compared to conventional alkali metal-ion batteries. However, there are still two severe challenges to confront, including structural collapse for the graphitic carbon cathode due to the intercalation of anions with large size and limited specific capacity of cations intercalation for the graphitic carbon anode, rendering poor rate performance, unsatisfactory cyclability, and insufficient energy density. Herein, a simple design is proposed to prepare cathode and anode materials for PF6- and Li+ intercalation in one synthesis system by regulating boron content in the complex of amino acid with iron (III). The graphitic mesoporous carbon cathode with minimal defect sites shows a superior rate performance and cycling stability for PF6- intercalation. The boron-doped porous carbon anode shows a high capacity of up to 606 mAh g(-1) for Li+ storage by introducing abundant defects. The DIB assembled by the above cathode and anode can exhibit a maximum energy density of 130 Wh kg(-1) at a power density of 580 W kg(-1) and an energy density of 74 Wh kg(-1) at an ultrahigh power density of 29000 W kg(-1).

Automated summary

Dual-ion batteries (DIBs) have attracted much attention due to their high energy density, low cost, and environmental friendliness. This study proposes a simple design to prepare cathode and anode materials for PF6- and Li+ intercalation, addressing the challenges of structural collapse and limited specific capacity. The DIB assembled with these materials exhibits excellent rate performance and energy density.