在全球能源转型的大背景下，可充电池是解决可再生能源存储问题的关键。以金属镁（Mg）为负极的二次电池体系具备能量密度高、成本低、安全性好等优势，是极具应用前景的新型储能体系。然而，电解液长期以来限制着镁二次电池的发展，开发稳定且电化学性能优异的镁电解液至关重要。Mg2+较高的电荷密度和较低的还原电势导致镁负极界面钝化问题显著，复杂的溶剂化结构使得镁电池电解液和电极-电解液界面难以得到科学调控。针对这些关键科学问题和技术挑战，本论文以镁二次电池电解液设计及其对电极-电解液界面的调控为主要研究内容，取得了如下研究成果： （1）提出了一种双（2,2,2-三氟乙基）醚（BTFE）共溶剂调控含氯电解液溶剂化结构和电极-电解液界面的通用策略。分子动力学模拟和实验表征发现，BTFE不仅可以促进带电离子团簇的生成，提高离子电导率；而且能够诱导电解液在镁负极表面分解生成固体电解质中间相（SEI），提升电池的循环寿命。BTFE共溶的镁锂氯复合物电解液可在20.0mA·cm2的超高电流下实现金属镁的可逆沉积-溶解。Mg//CuS电池在800次循环后放电比容量高达160 mAh·g-1，Mg//Mo6S8电池可在80 C的超高倍率下工作10000次。 （2）设计合成了一种新型电解质镁盐Mg(pftb)2；该镁盐在四氢呋喃（THF）中能够有效助溶MgCl2，从而制备出了一款全氟化醇基全镁电池电解液Mg(pftb)2+MgCl2/THF。实验和理论计算分析了该电解液的电化学活性物质，该物质具有合适的分子轨道能级，使得Mg(pftb)2+MgCl2/THF电解液能够在镁负极表面原位构筑SEI。利用先进的材料表征技术和电化学测试方法对SEI的厚度、组分、结构和性质进行分析，结果表明稳定的SEI是实现镁负极超长电化学循环寿命（8100小时）的主要原因。 （3）发展了一种使用强极性添加剂（1-甲基咪唑，MeIm）调控传统镁盐电解液溶剂化结构的方法，改善了镁负极在传统电解液中的沉积-溶解行为。理论计算和实验表征结果证实了高施主数和高介电常数的MeIm能够有效参与Mg2+溶剂化过程，辅助镁盐在醚类溶剂中的解离，减弱阴阳离子之间的相互作用，在提升电解液离子电导率的同时有效抑制阴离子对镁负极的钝化，对拓展无腐蚀且商业化的传统电解液在镁二次电池中的应用极具潜力。

In the context of global energy transformation, rechargeable battery is the key to solve the problem of renewable energy storage. Rechargeable magnesium (Mg) battery is one of the promising energy storage systems with high theoretical specific capacity, low cost, and high safety. However, the development of rechargeable Mg battery has been limited by electrolyte for a long time, so it is very important to develop stable Mg electrolyte with excellent electrochemical performance. The high charge density and low reduction potential of Mg2+ lead to the obvious passivation problem of Mg anode. The complex solvation structure makes it difficult to scientifically control the electrolyte and the electrode-electrolyte interface of Mg batteries. In view of these key scientific problems and technical challenges, this paper focuses on the Mg electrolyte design and its regulation effect on the electrode-electrolyte interface, and has obtained the following research results: (1) A general strategy for regulating the solvation structure of chlorine-containing electrolyte and the electrode-electrolyte interface by using a bis(2,2,2-trifluoroethyl) ether (BTFE) cosolvent was proposed. Molecular dynamics simulations and experimental characterization showed BTFE could not only promote the formation of charged ion clusters and thus significantly increased ionic conductivity, but also induced formation of a solid electrolyte interphase (SEI) through the electrolyte decomposition, which was beneficial to cycle life of battery. The BTFE cosolvated magnesium lithium chloride complex electrolyte supported reversible Mg deposition-dissolution at a current density as high as 20.0 mA·cm-2. The Mg//CuS cell maintained a high specific capacity of 160 mAh·g-1 after 800 cycles. The Mg//Mo6S8 cell could operate 10000 cycles at an ultra-high rate of 80 C. (2) A perfluorinated tert-butoxide magnesium (Mg(pftb)2) salt was designed and synthesized, which significantly increased the solubility of MgCl2 in tetrahydrofuran (THF) to form a perfluorinated alkoxide-based all-magnesium salt electrolyte Mg(pftb)2+MgCl2/THF. The experiments and theoretical calculations were conducted to analyzed the electrochemically active species, and the proper molecular orbital energy level of this active species enabled in situ formation of a SEI on Mg anode. The thickness, composition, structure, and properties of SEI were analyzed by advanced material characterization techniques and electrochemical tests. The results showed that stable SEI was the main reason for the ultra-long electrochemical cycle life (8100 h) of Mg anode. (3) A method of using strong polar additives (1-methylimidazole, MeIm) to control the solvation structure of conventional Mg salt electrolyte was developed, which improved the plating-stripping behavior of Mg metal anode in conventional electrolyte. The theoretical calculation and experimental characterization confirmed that MeIm with high donor number and high dielectric constant could effectively participate in the solvation of Mg2+, assist the dissociation of Mg salts in ether solvents, weaken the interactions between anions and cations, and then improve the ionic conductivity of electrolyte and inhibit the passivation of Mg anode by anions, simultaneously. It has great potential to expanded the application of non-corrosive, commercialized and conventional electrolyte for rechargeable Mg battery.