Grid-scale energy storage technologies is important and in urgent need for the Chinese National strategy of “carbon peak and carbon neutrality ”. Among the most energy storage technologies, electrochemical energy storage technologies, such as batteries, shows the great advantages of simple structure and high efficiency, which is developing quickly and widely applicated for varied fields of EES. For the electrochemical energy storage technologies, the electrodes play the key role for the battery performances. Current batteries suffer from low energy/power densities, poor cycling stability and safety issues, it is important to tune the molecule and electronic structure of the electrodes, constructing stable electrode/electrolyte interface, in order to provide more redox active sites, accelerate the ion/electron transfer kinetics as well as guarantee the stable and reversible redox reactions.

      Electrodes with special composition and structure always show attracting electrochemical performances, but are difficult to be synthesized through conventional chemical methods. Multi-physical fields, such as electric, magnetic, plasma, for the precise regulation of the electrodes. Firstly, supercritical condition is introduced for the preparation of heteroatoms doped carbon with ultrahigh doping levels. P doped carbon with an ultra-high doping level (30%) is successfully synthesized and demonstrate an ultrahigh reversible capacity with low potential of 0. 54 V vs Na/Na⁺. Secondly, electronic and thermal fields are coupled for the precisely control of metal valence in the transition metal compounds. Compared to TiO₂, low valence Ti oxides, such as TiO, Ti₂O show higher electronic conductivity and electrochemical reactivity due to metal-like properties. In this work. Ti-O compounds with low Ti valence is prepared through the molten-salts electrosynthesis and deliver a high reversible capacity of 484 mAh g^-1 through the multi-electron conversion reactions. In addition, plasma was introduced for the surface modification of the electrodes for the construction of stable artificial SEI layers with certain species. Artificial SEI layers with certain species of LiF, Li₂C₂ and polythiophene are prepared through the plasma treatment. Benefiting from the high mechanical strength of LiF, low Li⁺ diffusion barrier of Li₂C₂ and flexible structure of the polythiophene, modified Li anodes exhibit an long-term cycling stability of 8000 h with dendrite free structure. When coupling with LiFePO₄, the full cell demonstrate longer cycling performances.