LAUSR

Narrowing the capacitance gap between the positive electrode and the negative electrode for the enhancement in the energy densities of Battery-Supercapacitor-Hybrid (BSH) devices is urgent and very important. Herein, a new strategy to synchronously improve the positive-negative system and reduce the capacitance discrepancies between two electrodes through the utilization of the same MOF-based precursors ([Ni(ATA)2(H2O)2)](H2O)3) has been proposed. The nickel/nitrogen codoped carbon (Ni@NC) materials, serving as the positive electrodes, deliver battery-type behaviors with the enhancement of capacities, which are even superior to the pristine carbon-based materials with large surface areas. Meanwhile, the HCl-treated Ni@NC materials (named as A-Ni@NC) are employed as the negative electrodes within the potential window of -1⁓0 V, and exhibit higher capacitances than that of the commercial activated carbon. With Ni@NC and A-Ni@NC as positive and negative electrodes in BSH devices, the as-fabricated cells display higher capacities and energy densities, more excellent cycling stabilities, and more superior capacity retentions, in comparison with those of the Ni@NC//AC cells. These results clearly confirmed that our strategy is successful and effective.