▎ 摘　　要

The ternary amorphous CuSeP2 was designed and prepared as the anode material of potassium ion battery for the first time, and its electrochemical performance was also investigated. After ball-milling with commercial graphene powder, it is used as the anode material for potassium ion battery with reversible specific capacity up to 300 mAh g-1, and the corresponding initial coulombic efficiency is close to 60%. What's more, the specific capacity remains above 150 mAh g-1 after 100 cycles at 200 mA g-1. When increasing the current density to 1000 mA g-1, the CuSeP2/graphene composites still has a potassium storage specific capacity of 100 mAh g-1. Our results show that the potassium storage mechanism of the ternary CuSeP2 anode material is a typical conversion reaction and the introduction of Cu can not only buffer the volume expansion during the subsequent electrochemical reaction, but also effectively enhance the electrochemical reversibility of potassium ion.