Sacrificial Template Strategy toward a Hollow LiNi_1/3Co_1/3Mn_1/3O₂ Nanosphere Cathode for Advanced Lithium-Ion Batteries

Abstract

In this work, a hollow LiNi_1/3Co_1/3Mn_1/3O₂ (H-NCM) nanosphere cathode with excellent electrochemical performance is developed for lithium-ion batteries. Preparation of the H-NCM nanospheres involves the sacrificial template method, in which carbon nanospheres work as the template and polyvinylpyrrolidone works as an additive. Structural and morphological analyses show that the as-prepared H-NCM nanospheres are highly uniform with diameters of approximately 50 nm and wall thicknesses of 10 nm. Electrochemical tests demonstrate that the H-NCM cathode not only manifests outstanding rate performance in the potential window of 2.5-4.5 V with high reversible specific capacities of 205.6, 194.9, 177.8, 165.9, 151.7, 126.0, and 115.3 mA h g^-1 at 0.1, 0.2, 0.5, 1, 2, 5, and 10 C, respectively, but also delivers excellent stability with a capacity retention of 60.1% at 10 C after 2000 cycles. The superior electrochemical performance of the H-NCM cathode can be put down to the distinctive hollow interior structure with thin nanostructured walls, which can synergistically benefit the significantly enhanced rate capability and cycling stability.