Facile and rapid construction of NiFe-LDH foam with abundant oxygen vacancies as high-performance supercapacitor negative electrode

Herein, a high-performance supercapacitor negative electrode was constructed by soaking the NiFe foam in H2SO4 just for 5 min. Benefiting from the in-situ route, hierarchical porous structure and abundant oxygen vacancies, the obtained NiFe layered double hydroxide foam presented excellent capacitive performance (1.54F cm−2 at 5 mA cm−2). Furthermore, the assembled hybrid supercapacitor yielded a high energy density of 0.15 mWh cm−2 and an excellent cycle life with 86.7% capacitance retention even after 7000 cycles, which outperformed the previously reported asymmetric supercapacitors. This work definitely shed light on the possible industrialization of the negative electrode material