With the boom in electric vehicles (EVs), there is an increasing demand for high-performance lithium-ion batteries. Lithium manganese iron phosphate (LMFP) has emerged as an enhanced variation of LiFePO₄ (LFP), offering an energy density 10%–20% greater than that of LFP. Structural distortion caused by the Jahn–Teller effect decreases the capacity and voltage platform, thus restricting the commercialization of this material. Herein, ideas to overcome these challenges, including the crystal structure of LMFP and strategies to mitigate the Jahn–Teller distortion, are first explored. Then, the migration pathways of Li⁺ during charging and discharging and the phase transition mechanisms that affect the material’s performance are discussed. Next, the optimal Mn:Fe ratio for achieving the desired performance is described. The influences of various synthesis and modification methods on the morphology and structure of LMFP are reviewed. Additionally, different modification techniques, such as doping and coating, to enhance the performance of LMFP are highlighted. Finally, an overview of the current state of research on the recycling and reuse of LMFP is provided. By addressing these key topics, this paper offers a theoretical foundation for the further development of LMFP, thus contributing to its eventual commercialization.

Covalent organic frameworks (COFs), a novel class of crystalline porous materials constructed by covalent bonds, possess ordered porous structures via thermodynamically controlled polymerization reactions. Because of their structurally diverse, regular pore structures, high surface area, and thermal stability can be functionally tailored through different synthetic methods to meet the needs of various applications including for secondary batteries. This review summarized recent efforts that have been devoted to designing and synthesizing COF-based materials for battery applications, including electrode materials, electrolytes, and separators. Unique characteristics of COFs allow for the rational design of targeted functions, suppression of side reactions, and promotion of ion transport for batteries. This review clarified recent research progress on COF materials for lithium-ion batteries, lithium–sulfur batteries, sodium-ion batteries, potassium-ion batteries and so on. This review pointed out the structure and chemical properties of COFs, as well as new strategies to improve battery performance. Furthermore, we concluded the major challenges and future trends of COF materials in electrochemical applications. It is hoped that this review will provide meaningful guidance for the development of COFs for alkali-ion batteries.

All-solid-state lithium batteries (ASSLBs) based on sulfide solid electrolytes (SEs) are one of the most promising strategies for next-generation energy storage systems and electronic devices. However, the poor chemical/electrochemical stability of sulfide SEs with oxide cathode materials and high interfacial impedance, particularly due to physical contact failure, are the major limiting factors to the development of sulfide SEs in ASSLBs. Herein, the composite cathode of MOF-derived Fe₇S₈@C and Li₆PS₅Br fabricated by an infiltration method (IN–Fe₇S₈) with dissoluble sulfide electrolyte (dissoluble SE) is reported. Dissoluble SE can easily infiltrate the porous sheet-type Fe₇S₈@C cathode to homogeneously contact with Fe₇S₈ nanoparticles that are embedded in the surrounding carbon matrixes and form a fast ionic transport network. Benefiting from applying dissoluble SE and Fe₇S₈@C, the IN-Fe₇S₈-based cells displayed a reversible capacity of 510 mAh g⁻¹ after 180 cycles at 0.045 mA cm⁻² at 30 °C. This work demonstrates a novel and practical method for the development of high-performance all-sulfide-based solid state batteries.

Boron (B)-doped LiNi_0.6Co_0.2Mn_0.2O₂ cathode materials were prepared by oxalate co-precipitation and subsequent heat treatment. The effects of doping with different boron sources (B₂O₃, H₃BO₃ and LiBO₂) on the morphology, structure and electrochemical properties of the materials were investigated. The X-ray diffracation and Rietveld refinement revealed that the B element was successfully doped into the material lattice. The electrochemical performance characterization showed that the doping effect of B₂O₃ was the best, with excellent rate performance (the specific discharge capacity was 145.1 mA·h/g at 5 C) and long-term cycle stability (the capacity retention ratio was 84.5% after 300 cycles at 1 C). The enhanced electrochemical performance is attributed to the fact that boron doping effectively reduces the surface residual lithium compound, enhances the structural stability of the material, effectively inhibits the voltage drop and improve the polarization phenomenon, and reduces the charge transfer resistance, thus inhibiting the capacity decay and achieving excellent electrochemical performance.