Co3O4 Nanosheets as Battery-Type Electrode for High-Energy Li-Ion Capacitors: A Sustained Li-Storage via Conversion Pathway

We report the excellent charge storage performance of high-energy Li-ion capacitors (LIC) fabricated from the mesoporous Co3O4 nanosheets as the conversion-type battery component and Jack fruit (Artocarpus heterophyllus) derived activated carbon as a supercapacitor electrode, especially at high temperatures (50 and 40 degrees C). Prior to the fabrication, the electrochemical prelithiation strategy was applied to Co3O4 to alleviate the irreversibility and enrich the Li-ions for electrochemical reactions (Co-0 + Li2O). The LIC delivered a maximum energy density of similar to 118 Wh kg(-1) at a high temperature of 50 degrees C. The significant difference is observed at a high rate of 2.6 kW kg(-1) at 50 degrees C with excellent cycle stability up to 3000 cycles, with a retention of similar to 87% compared with the LIC cycled at room temperature (similar to 74%). The magnificent electrochemical performance clearly demonstrates that the mesoporous structure and residual carbon synergistically facilitated the Li+/electron transport and hinder undesirable side reactions with electrolytes to realize high-energy density at high temperatures.