Double‐Hollow Porous Heterostructured CoP/Cu 3 P Microspheres for High‐Performance Asymmetric Supercapacitors

ABSTRACT CoP has become a research hotspot for supercapacitor electrode materials because of its considerable theoretical capacitance and metalloid nature, but its commercial application remains hampered by structural instability and sluggish ion kinetics. Herein, a high‐performance double‐hollow porous heterostructured CoP/Cu 3 P microsphere is assembled using a hydrothermal reaction and phosphating process. The collaborative interaction between the heterostructure and double‐hollow microsphere leads to a suppression of volume change, expansion of the active surface, and ion diffusion. The developed CoP/Cu 3 P sample demonstrates a specific capacitance of 1172.4 F g −1 at 1.0 A g −1 along with outstanding rate capability (capacitance retains 58.5% of its value as current density increases by 20 times), and cycling stability (i.e., 10,000 cycles, 90.0% of its original capacitance). Post‐cycling analysis shows minimal morphological change, validating the structural robustness of the CoP/Cu 3 P microspheres. Furthermore, operating at a high voltage of 1.6 V, the asymmetric CoP/Cu 3 P supercapacitor demonstrates remarkable energy density (44.1 Wh kg −1 ) and power density (846.8 W kg −1 ) while maintaining 84.7% of the maximum capacity even after 20,000 cycles, highlighting its exceptional performance. The influence of the electrochemical performance is further verified through first‐principles calculations and indicates the promising application prospects in electrical energy storage.