Formation of holes into granule Li₄Ti₅O₁₂ anode for enhanced performance of hybrid supercapacitors

Hybrid supercapacitors are being studied as a next-generation energy storage device that bridge supercapacitor and lithium-ion battery. However, an imbalance of two electrodes of hybrid supercapacitors, especially due to the slow lithium ion kinetics at anode is the one of the most important problems. To solve this problem, we have demonstrated optimized hybrid supercapacitor performance by applying the punched granule Li₄Ti₅O₁₂ (P-LTO) via mechanical punching as a high power anode. The hybrid supercapacitors based on P-LTO anode and activated carbon delivers not only high specific capacity of 57 F/g and excellent long-term cycling of 99% after 14,000 cycles but also remarkable rate capability of 90.6% even at a high rate of 4 A/g, mainly due to i) increase in the total effective contact area, ii) efficient electrolyte impregnation and iii) effective dispersion of hydrogen fluoride attack.