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The controllable morphology and size Li-rich Mn-based layered oxide LiNiCoMnO with micro/nano structure is successfully prepared through a simple coprecipitation route followed by subsequent annealing treatment process. By rationally regulating and controlling the volume ratio of ethylene glycol (EG) in hydroalcoholic solution, the morphology and size of the final products can be reasonably designed and tailored from rod-like to olive-like, and further evolved into shuttle-like with the assistance of surfactant. Further, the structures and electrochemical properties of the Li-rich layered oxide with various morphology and size are systematically investigated. The galvanostatic testing demonstrates that the electrochemical performances of lithium ion batteries (LIBs) are highly dependent on the morphology and size of LiNiCoMnO cathode materials. In particular, the olive-like morphology cathode material with suitable size exhibits much better electrochemical performances compared with the other two cathode materials in terms of initial reversible capacity (297.0 mAh g) and cycle performance (95.4% capacity retention after 100 cycles at 0.5 C), as well as rate capacity (142.8 mAh g at 10 C). The excellent electrochemical performances of the as-prepared materials could be related to the synergistic effect of well-regulated morphology and appropriate size as well as their micro/nano structure.

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Lithium-rich layered materials, Li 1+x M 1Àx O 2 (M ¼ Mn, Ni, Co), have been under intense investigation as highperformance cathode materials for lithium ion batteries due to their high discharge capacity, low cost and environmental benignity. Unfortunately, the practical uses of these oxides have so far been hindered by their severe capacity and voltage fading during high voltage cycling (>4.5 V vs. Li/Li + ). In an attempt to overcome these problems, herein, a novel lithium-rich Li 1.14 [Mn 0.60 Ni 0.25 Co 0.15 ] 0.86 O 2 microsphere with heterogeneous distribution in the composition has been reasonably designed and successfully synthesized via a co-precipitation method. The chemical composition in the spherical particle is gradually altered by increasing the Mn concentration while reducing the Co content from the particle center to the outer layer. At the same time, the Ni content remains almost constant throughout the particle. The coin cell with the heterogeneous cathode material delivers a high discharge capacity of over 230 mA h g À1 between 2.0 V and 4.6 V, and shows excellent cyclic stability due to the continuous increase of the stable tetravalent Mn towards the outer surface of the spherical particles, corresponding to 93.8% capacity retention after 200 cycles at 0.5 C. More importantly, the as-prepared material exhibits a significantly lower discharge voltage decay compared with conventional materials, which may mainly be ascribed to the suppression of the layered-to-spinel transformation in the Co-rich/Mn-depleted regions of the spherical particle. The capacity and voltage fading of the lithium-rich layered material are simultaneously suppressed by the special architecturual design, and the results here will shed light on developing cathode materials with special structures and superior electrochemical properties for highperformance lithium ion batteries. Fig. 9 (a) The cycle performance of the Li/HL and Li/CL cells between 2.0 and 4.6 V at a rate of 5 C; the continuous charge/discharge curves of the (b) HL and (c) CL electrodes.This journal is