This review clearly highlights the recent advances of various synthetic and modification methods in improving the performances of Li₂MnSiO₄cathodes for LIBs.

By using a multifunctional high-energy biomolecule—adenosine triphosphate (ATP)—we fabricated high-energy quantum dots (HEQDs) with a feature size of less than 10 nm and used them in high-power lithium-ion batteries. We introduced high-energy phosphate bonds into the crystal structure of LiFePO₄ nanoparticles and synthesized the mesoporous biocarbon nanowire coated LiFePO₄ with HEQDs (MBCNW-LFP-HEQDs) by using ATP as a phosphorus source, a nucleating agent, a structural template and a biocarbon source. HEGDs were homogeneously formed inside the ultra-thin LiFePO₄ nanosheet and the mesoporous biocarbon nanowire network structure was coated on the surface of the nanosheet. In LiFePO₄ nanoparticles, HEQDs result in more storage sites of Li⁺ ions and easier transfer kinetics of electrons and lithium ions, where the kinetic transformation path between LiFePO₄ and FePO₄ is rather different from the path deduced from its equilibrium phase diagram. Compared to the usual LiFePO₄ nanoparticle (10–100 nm) cathode, the MBCNW-LFP-HEQD cathode shows the best first discharge capacity of 197 mA h g⁻¹ at the 0.1 C rate, which is higher than the theoretical capacity of LiFePO₄ (170 mA h g⁻¹). After 100 cycles at varied current rates: 0.1, 0.5, 1, 5 and 10 C, this cathode still delivered a high discharge capacity of 180 mA h g⁻¹ and an ultra-high coulombic efficiency close to 100%. This is attributed to the quantum tunneling of HEQDs in LiFePO₄ nanoparticles and better percolation of mesoporous biocarbon nanowire coating network structures. This work is instructive for fabrication and design of new types of electrochemical energy conversion and storage devices with extraordinary properties and functions.

LiFePO₄ has emerged as the cathode material of choice for high-power lithium-ion batteries as it offers much higher energy density and excellent structural stability than other cathode materials. However, its performance factors such as energy density, power density, and cycle life depend on the nanoparticle morphology of LiFePO₄. This paper provides an overview of the effects of nanoparticle morphology on the electrochemical performances of LiFePO₄. The crystal structure and structural model of LiFePO₄ are depicted in detail. The synthetic methods, formation principles, characteristics and morphology–performance relationships of LiFePO₄ nanoparticles, including LiFePO₄/C nanocomposite particles, LiFePO₄ nanorods and LiFePO₄ nanowires are investigated. This is a typical review but it does not cover all nanostructured LiFePO₄ cathodes reported in the literature. Our major goal is to highlight some new progress in using the LiFePO₄ nanoparticles as cathodes to develop lithium batteries with high energy density, high rate capability, and excellent cycling stability.

Various composite membranes with inorganic particles for lithium ion batteries are summarized and discussed.