NiCo-MOF directed NiCoP and coconut shell derived porous carbon as high-performance supercapacitor electrodes br

摘要

Bimetallic mickel/cobalt metal-organic frameworks(MOFs) have showed important applications as super-capacitor electrode materials due to their rich redox active sites, regular pore structure and huge specific surface area. But their specific energy and capacitance are limited. In this paper, a MOFs phosphorization strategy was proposed for preparing high-performance NiCo bimetallic phosphide nanosheets (NiCoP) by simple OHion etching and phosphorization. The formed nanosheet structure possesses a huge specific surface area, which is beneficial for the Faraday reaction. The as-prepared Ni1Co1-10P nanosheets present significant synergy among transition metal ions, which contributes to enhanced electrochemical performance. Because of structural and composition advantages, the optimized Ni1Co1-10P nanosheets show a superior specific capacitance (1188.4 F g1 at 1 A g1) than corresponding hydroxide (Ni1Co1-OH) and Ni1Co1-MOF precursors. The as-assembled asymmetric supercapacitor (ASC) using Ni1Co1-10P nanomaterial as the positive electrode and coconut shell derived porous carbon (EC) with huge surface area and electric double layer capacitor (EDLC) property as negative electrode delivers a high specific capacitance of 135.5 F g1 at 1 A g1 and a maximum energy density of 55.01 Wh kg1 at 849.94 W kg1 as well as excellent capacitance retention (86.12 after 10,000 cycles). Therefore, the prepared Ni1Co1-10P electrode materials have a broad application in high-performance supercapacitors.