3D hierarchical Ni(PO3)2 nanosheet arrays with superior electrochemical capacitance behavior

A novel electrode material, three-dimensional (3D) hierarchical Ni(PO3)(2) nanosheet arrays, is explored via a rational topotactic strategy combining hydrothermal growth with subsequent phosphorylation treatment. The as-synthesized Ni(PO3)(2) nanosheet arrays self-supported on activated carbon cloth (Ni(PO3)(2)@ACC) exhibit superior electrochemical capacitive behaviors to a Ni(OH)(2) analogue with similar structural characteristics. The areal and mass specific capacitances of the arrays are as high as 4.43 F cm(-2) at a current density of 2 mA cm(-2) and 2237 F g(-1) at similar to 1 A g(-1), respectively, which is comparable to the best reported results for Ni-based and Me-POx battery-type electrodes. Furthermore, even at a high rate of 10 mA cm(-2), the arrays maintain similar to 90% charge retention after 2000 cycles, suggesting their robust stability and their very promising applications for energy storage.