Radiation synthesis of Ni3(NO3)2(OH)4 nanosheets for high-performance supercapacitor

Ni 3 (NO 3 ) 2 (OH) 4 positive electrode material was for the first time synthesized by gamma ray radiation under ambient conditions, and systematically investigated the synthesis mechanisms and electrochemical performance. The electrochemical performance of Ni 3 (NO 3 ) 2 (OH) 4 electrode can be regulated by controlling the absorbed dose. Ni 3 (NO 3 ) 2 (OH) 4 -200 kGy displays a remarkable electrochemical performance for supercapacitor, including a high specific capacity (1,086.7   C   g –1 at 1   A   g –1 ), good rate capability (50.6% at 15   A   g –1 ), fast Faraday reaction kinetics, and excellent electrochemical cycle stability (90.8% retention at 5   A   g –1 , after 5,000 cycles). Furthermore, the assembled Ni 3 (NO 3 ) 2 (OH) 4 -200 kGy//AC hybrid device exhibits a notable energy density of 99.8   Wh   kg –1 at a power density of 849   W   kg –1 (1   A   g –1 ), and excellent electrochemical cycle stability, retaining ~92.5% of its initial capacitance after 5,000 cycles at 1   A   g –1 . This work provides a new reaction pathway for the synthesis of inorganic materials and expands the potential application of radiation technology for electrode materials.