Preparation of the Amorphous NiCoP Nanosheet Array on Carbon Cloth for High‐Performance Solid‐State Hybrid Supercapacitor

Abstract The outstanding performance of amorphous transition metal phosphides (TMPs) has garnered significant attention in the field of energy storage devices. However, the current approaches for obtaining TMPs require a high phosphidation temperature of over 350 °C, which cause a rise in crystallinity and inferior supercapacitive performance, along with the insufficient utilization of phosphidation agents. In this work, we designed a specially‐made quartz reactor to address this challenge. Using the specially‐designed reactor, the amorphous NiCoP nanosheet array was successfully synthesized on carbon cloth at a relatively low phosphidation temperature of 280 °C. The resulting nanosheet array grown on carbon cloth exhibited a high specific capacity of 338.33 mAh g −1 at a current density of 1 A g −1 , along with exceptional cycling stability, retaining 92.3 % of its initial capacity after 1000 cycles. An asymmetric solid‐state hybrid supercapacitor assembled using the prepared amorphous NiCoP@CC‐1 material exhibited a high energy density of 50.98 Wh kg −1 at a power density of 800 W kg −1 while maintaining 92.7 % of initial specific capacity after 5000 cycles. The proposed approach is anticipated to facilitate the use of amorphous TMP materials in the development of high‐performance solid‐state hybrid supercapacitors.