Preparation and electrochemical properties of Cu 3 P/rGO nanocomposite protection strategy for lithium-ion batteries

Copper phosphide (Cu 3 P) has emerged as a promising new lithium-ion electrode material due to its high theoretical capacity and abundant earth resources. However, there are serious volume expansion and agglomeration problems in the charging and discharging process, resulting in poor electrochemical performance and low rate performance. We synthesized 3D Cu 3 P/rGO (CPG) composite nanomaterials by normal-temperature agitation and high-temperature calcination. The mechanism underlying the enhancement in the electrochemical behavior of the composite electrode material by the stable surface/interface structure of the composite material, the nanostructure of metal phosphide, and the synergistic effect between the nanostructure of the metal phosphide and the carbon material were investigated. As an active material, CPG showed good electrochemical performance. When the current density was 0.5 C, after 200 cycles, it still maintained specific capacity at 716.8 mAh g −1 , and it also showed good performance at high current density (after 330 cycles, at 5 C), with specific capacity of 496.6 mAh g −1 . At the same time, the CPG composites showed obvious pseudocapacitive characteristics (59.6% of the total capacitance was accounted for when the scanning rate was 0.4 mV s −1 ). The results show that the modified composites of rGO effectively improved the electrochemical performance of Cu 3 P. This provides theoretical support for the development of new lithium-ion battery anode materials.