Hierarchical Li-rich oxide microspheres assembled by {010} exposed primary grains for high-rate lithium-ion batteries

Layered Li-rich oxides (LLOs) with high capacity exceeding 300 mAh g–1 and low cost are regarded as a promising candidate for high energy-density lithium-ion batteries. However, it usually presents sluggish Li+ kinetics and low tap-density, resulting the poor rate capability and volumetric energy-density. Here, the wide particle size distribution of LLOs microspheres assembled by {010} exposed primary grains are rationally proposed to solve these above issues. The high specific capability of ~295 mAh g−1 at 0.1C and superior cycling stability (capacity retention of 90.6% after 100 cycles) are delivered. The close stacking caused by the coexistence of large and small secondary particles gives rise to a high tap-density of 2.26 g cm−3, corresponding to a high volumetric energy-density of above 2350 Wh L−1. TEM results confirm that the lateral direction nanosheets belong to the electrochemically active {010} planes, which further results in the improved Li+ kinetics during redox. As a result, the excellent high-rate capability of 110 mAh g−1 is achieved even at 20C. GITT tests elucidate that the active {010} exposed planes exhibit superior Li+ diffuse kinetics. This feasible strategy can be expanded to enhancing the Li+ kinetics of other NCM-based layered cathodes for alkali rechargeable batteries.