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In order to develop lithium-ion batteries with high energy density, prelithium technology has attracted extensive attention. Li5FeO4was successfully prepared by molten salt method with LiNO3-LiOH mixed lithium salt as reaction medium and lithium source, and nano Fe2O3 as iron source in this work. Li5FeO4 as cathode prelithiation additive is applied to lithium-ion batteries. The synthesis conditions of Li5FeO4 were optimized by orthogonal experiment, and the effect of synthesis conditions on the electrochemical properties of the material was discussed. Li5FeO4 was added to the surface of LiFePO4 positive electrode and assembled with graphite negative electrode to form a full cell. Its effect on the electrochemical performance of the full cells and the mechanism of reducing the initial capacity loss of lithium-ion batteries were studied. The results show that Li5FeO4 cathode prelithiation additives with high purity, small particle size and outstanding electrochemical performance can be prepared by molten salt method. When Li5FeO4 with a mass fraction of 2.8%(based on the percentage of active materials mass) was added, the discharge specific capacity of first cycle for the LiFePO4/graphite full cell was 150 mAh·g-1 at 0.05 C, which was 8.5% higher than that without adding, after 100 cycles at 0.2 C. the capacity still increased by 7.1%, and the irreversible capacity of the svstem was restored.

Flexible energy storage devices are at the forefront of next-generation power supplies, one of the most important components of which is the gel electrolyte. The dual network gel electrolyte for PAM/P123 zinc ion batteries was prepared by free radical polymerization. It was found that the addition of a small amount of triblock copolymer P123 can macroscopically improve the tensile strength, toughness and compressive strength of the gel electrolyte. Microscopically, the gel skeleton forms 0.6 μm mesopores and increases the surface pore distribution density, thereby improving the wettability of the electrolyte. The PAM/P123 series electrolytes not only have a high average swelling rate, but also have a higher conductivity than pure PAM electrolyte in the range of -30℃ to 65℃. Among which, PAM/P123-2 is a series of electrolytes with the best performance, with an average swelling rate of 1920.79%, and the conductivity at 0℃ is 36.2 mS·cm-1.The Zn/MnO2 battery prepared by using PAM/P123-2 gel electrolyte is stable during cycling at 0℃, with the capacity retention rate reaching 82.39% after 1000 cycles.

Solid state lithium battery is expected to be one of the next generation of battery systems with high energy density in the field of high energy. Based on the constructure characteristics and related formation mechanism of interface between solid polymer electrolyte and lithium anode, the impact of interface contact, interface chemistry and electrochemical reaction, and moreover, the growing process of lithium dendrite and other problems on the interface stability and compatibility were systematically discussed in this review.Thus, the application of doping modification, structure design, and other methods for the interfaces between polymer matrix and lithium anode were also emphasized. In addition, the common interface characterization methods and their applications on the interface between solid polymer electrolyte and lithium anode were also reviewed. Finally, based on the relevant strategies of designing and constructing a stable polymer solid electrolyte-lithium anode interface, the development prospects of interface optimization methods such as doping and core layer design were analyzed and prospected in this paper.

Lithium metal batteries (LMBs) represent the most promising next‐generation high‐energy density batteries. The solid electrolyte interphase (SEI) film on the lithium metal anode plays a crucial role in regulating lithium deposition and improving the cycling performance of LMBs. In this review, we comprehensively present the formation process of the SEI film, while elucidating the key properties such as electronic conductivity, ionic conductivity, and mechanical performance. Furthermore, various approaches for constructing the SEI film are discussed from both electrolyte regulation and artificial coating design perspectives. Lastly, future research directions along with development recommendations are also provided. This review aims to provide possible strategies for the further improvement of SEI film in LMBs and highlight their inspiration for future research directions. [ABSTRACT FROM AUTHOR]

As promising alternatives to liquid electrolytes, polymer electrolytes attract much research interest recently, but their widespread use is limited by the low ionic conductivity. In this study, we use electrostatic spinning to introduce particles of an ionic conductor into polyacrylonitrile (PAN) fibers to prepare a porous membrane as the host of gel polymer electrolytes (GPEs). The relevant in‐situ produced GPE performs a high ionic conductivity of 6.0×10−3 S cm−1, and a high lithium transfer number (tLi+) of 0.85 at 30 °C, respectively. A symmetrical Li cell with this GPE can cycle stably for 550 h at a current density of 0.5 mA cm−2. While the capacity retention of the NCM|GPE|Li cell is 79.84 % after 500 cycles at 2 C. Even with an increased cut‐off voltage of 4.5 V, the 1st coulomb efficiency reaches 91.58 % with a specific discharge capacity of 213.4 mAh g−1. This study provides a viable route for the practical application of high energy density lithium metal batteries. [ABSTRACT FROM AUTHOR]