A unique nanosheet assembled CoMn2O4 hollow nanospheres as superior cyclability anode materials for lithium-ion batteries

Although promising, the use of single-phase ternary mixed transition-metal oxides as anode materials of lithium-ion batteries is still accompanied with drawbacks, such as inferior cycling stability. To address these issues, the application of morphologically elaborate nanostructured materials has been suggested. This paper presents herein a new approach to constructing uniformly nanosheet assembled CoMn2O4 hollow nanospheres, which involves a combustion method assisted by polystyrene nanospheres (PS) templates. To realize the desired morphologies, a crucial step is the controlled growth of metal ions with specific molar ratios in a sulfonated PS gel and a key control parameter is the heating rate needed to ensure hollow architecture. The resulting CoMn2O4 hollow nanosphere anode exhibits satisfactory initial discharge capacity of 1269.1 mAh g( -1) and charge capacity of 790.6 mAh g(-1) at 200 mA g(-1). When experiences 50 cycles in the potential window of 0.1-3.0 V, the anode also demonstrates superior cycling stability with capacity preservations are, respectively, 90.5%, 86.4% and 81.2% at 200 mA g(-1), 800 mA g(-1) and 1000 mA g(-1). These merits of hollow nanospheres lie in the fact that such structure can provide rapid ionic/electronic access to the active material and accommodate the volume variations of the CoMn2O4 anode with repeated Li(+ )insertions/extractions processes. (C) 2019 Elsevier B.V. All rights reserved.