Li-ion batteries (LIBs) are one type of more and more widely used devices for energy storage and power supply in which cathode materials are playing a relatively more decisive role at current stage. In this review, we start with pioneeringly commercialized LiCoO₂ (LCO) with a layered rhombohedral structure (space group $R\overline{3}m$) to discuss novel sequentially emerging LCO-derived layered oxides from the perspectives of both cobalt content reduction and performance improvement. Emphasis is placed on the improvement of high-voltage performance of LCO and Co-reduced/free layered oxides, including Co-reduced high-nickel layered oxides, Co-free Li-rich layered oxides, and Ni-based layered oxides cathodes, and their underlying mechanisms via different strategies. Also, possibly matched carbon and silicon-based anode materials are briefly discussed. The common issues and prospects of the layered oxides cathodes and their potential anodes are summarized and commented on. This review can help understand the emergence logics of novel layered oxides with gradually vanishing cobalt involved, provide insights about the underlying mechanisms of performance enhancement pertaining to particular strategies, and even inspire the discovery of novel cathode materials with high performance and low cost.

LiFePO₄ nanoparticles with different morphologies and sizes were synthesized via a solvothermal method using environmentally benign and low-cost glycerol as the surfactant. The morphology, size, and structure of the particles were found to relate closely to the concentration of glycerol. Oriented linked LiFePO₄ nanorods along mostly non-[010] were obtained with the proper concentration of glycerol. The nanorods showed good electronic and ionic conductivities, resulting in superior rate capability and cycling performance. This performance was attributed to the oriented linkages along mostly non–[010], the small particle size along [010], and the occupation of Li at Fe sites. Initial discharge capacities of 162.4 mA·h·g^–1 at 0.1 C and 102.1 mA·h·g^–1 at 30 C were achieved, with capacity retentions after 500 cycles at 5 and 20 C of 99.5% and 93.2%, respectively. At the rate of 40 C, the solid-solution phase transition dominated during lithiation and delithiation of all samples.