Ultrahigh areal capacity of self-combusted nanoporous NiCuMn/Cu flexible anode for Li-ion battery

Abstract

Nanostructured transition metal oxides (TMOs) have shown extraordinary promise as anode materials for Lithium ion battery but still been challenging for practical applications due to their low conductivity and activity with high loading mass. Herein, we prepare an integrated high-loading-mass TMOs based anode with 3D nanoporous structure and metallurgical bonding interface between oxide and current collector by self-combustion and subsequently mild annealing of the nanoporous NiCuMn (np-NiCuMn). Self-combustion, caused by the high surface energy of np-NiCuMn, induces ligament coarsening and deep surface oxidation of the alloy, which consumes all the energy quickly and form metal core and oxide shell structure with loading mass up to 7.3 mg cm−2. Mild annealing in H2 at 250 °C creates robust vacancies in oxide layers (6.9 mg cm−2 of oxide retention) with some precipitated Cu doping, which not only provides more Li+ storage sites but also further enhance the electron/ion transportation in the anode. Consequently, the flexible integrated electrode demonstrates an ultrahigh area capacity of up to 9.48 mAh cm−2 at a current density of 0.5 mA cm−2, as well as excellent rate performance and cycle stability. This work is expected to open a cost-effective and large-scale route to prepare high-capacity electrodes for next-generation energy storage devices.