Ti3SiC2-coupled NiCoMn LDH nanocomposites as positive electrode for high performance supercapacitors

Abstract

The layered structure of layered double hydroxides (LDH) is essential for its usage as an electrode material, yet the absence of efficient charge exchange across layered structures severely limits LDH’s employment in supercapacitors. In this work, NiCoMn LDH (abbreviated as LDH) and its composite with Ti3SiC2 MAXenes in 3 %, 6 % and 12 % by weight (abbreviated as LDH/M3, LDH/M6 and LDH/M12, respectively) were synthesized using the probe sonication method. The LDH/M6 electrode had a higher maximum specific capacitance (566.6 F/g) than the LDH (480.83 F/g), LDH/M3 (508 F/g), and LDH/M12 (489.1 F/g) electrodes at a current density of 0.5 A/g, which is about 16 %, 11 %, and 14 % higher than the aforementioned electrodes, respectively, demonstrating the effectiveness of using Ti3SiC2 MAXenes nanosheets. At 0.5 A/g, the capacitance of the asymmetric supercapacitor’s ideal LDH/M6 electrode is 162.2 F/g, and the energy and power densities are 72.8 Wh/kg and 450 W/kg, respectively. Its stability results showed an impressive 93 % capacity retention after 4000 cycles. Further, its overall hybrid-type performance was confirmed by analyzing its diffusive-capacitive behavior, which demonstrated 32 % capacitive and 68 % diffusive behavior. This promising performance indicates that LDH/M6 can be used as electrode material in high-performance supercapacitors.