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To meet the demands in portable electronic devices, electric vehicles and stationary energy storage, it is necessary to prepare advanced lithium ion batteries (LIBs) with high energy density and fast charge and discharge capabilities. Cathode materials, which account for 40%–50% of the cost of a whole battery, play a decisive role in cell voltage and capacity. Moreover, the performances of the cathodes are also balanced by many other aspects, including cycle life, rate capability, safety, costs, and environmental benignity. Unfortunately, none of the currently available cathode materials (e.g. LiFePO4, LiNixCoyMn1−x−yO2 layered oxides and Li-rich layered oxides) can get all the quests in a single cell. The electrochemical performances of a cathode are closely connected with its structural features, such as the porosities, morphologies and specifically exposed surfaces, which can be tuned by delicate designs. Here, we review our work on the rational design and delicate preparation of a series of cathode materials with controllable microstructures. We reveal the synergistic effects of both reaction and mass transfer on the formation of these meso-scale structures and the improved electrochemical performances of the cathode materials. The review will provide a scientific basis for the large-scale production of meso-scale structured cathode materials, and lay theoretical and experimental foundation for the application of cathode materials in next-generation LIBs. [ABSTRACT FROM AUTHOR]

Abstract Nowadays nickel-rich LiNi x Co y Mn 1-x-y O 2 (0.5 < x < 1) cathode materials attract great research interests due to their high specific capacity in lithium ion batteries. However, poor cycling performance and serious safety concerns trade off their benefits. Here, we present an effective etching-induced coating strategy for surface modification of LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode materials by LiAlO 2. Hydrolysis of AlCl 3 creates H+ to etch the hydroxide precursor of LiNi 0.8 Co 0.1 Mn 0.1 O 2 and to induce oriented deposition of Al(OH) 3 layer on surface of the hydroxide precursor, which is transformed into uniform γ-LiAlO 2 coating on the LiNi 0.8 Co 0.1 Mn 0.1 O 2 particles after the subsequent lithium impregnating and annealing. The 2.2 wt% LiAlO 2 -coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode delivers a high rate capacity of 135.2 mAh g−1 at 10 C and long cyclability with capacity retention of 85.8% after 200 cycles at 0.5 C. In addition, the thermal stability of LiAlO 2 -coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 is significantly improved. The enhanced battery performances are due to partial Al3+ doping and Li+ conductive LiAlO 2 coating layer that provides well-connected networks for Li+ transport, improves the structural stability and prevents core materials from the attack by side products. Graphical abstract The detailed etching-induced coating strategy for the synthesis of LiAlO 2 -coated NCM811 materials. Image 1 Highlights • The etching-induced coating strategy was designed to prepare LiAlO 2 -coated NCM811. • The modified NCM811 exhibits better rate and cycle performance. • The modified NCM811 displays smaller overpotential especially at high rate. • The coating of LiAlO 2 significantly improves the thermal stability of NCM811. [ABSTRACT FROM AUTHOR]