随着全球经济的不断发展，人们对于能源的需求日益增加，电池储能系统的研发进程得到了有力推动，有关锂离子电池、锂硫电池和非锂金属电池等储能体系的研究热度不断上升。在这些储能系统中，锂硫电池由于具有高能量密度、原料易得且对生态环境友好等优势，得到了学者们的广泛关注。但随着对锂硫电池研究的不断深入，其固有缺陷也逐步呈现出来，例如正极活性材料硫的利用率低、电子传导性差，中间产物的高溶解度而引发的“穿梭效应”以及充放电前后硫的体积膨胀等问题都严重限制着其发展空间。

为了克服上述缺点，尤其是多硫化锂的穿梭效应，许多研究致力于设计合成新型的硫宿主材料以提高硫的利用率，同时对于电解质的优化和隔膜的修饰，以及锂负极的保护也是十分热门的领域。在以上优化途径中，通过向传统商用隔膜面朝正极侧覆盖一层功能性材料来抑制多硫化物在电解液中的迁移，被证明是一种有效的隔膜改性方法。进一步研究显示，过渡金属氧化物易能够通过路易斯酸碱作用对多硫化物产生化学吸附，因此本文将介孔Co₃O₄颗粒作为功能性涂层材料修饰隔膜，以提升锂硫电池的性能。

本文采用硬模版法制备具有三维孔道结构的介孔Co₃O₄（KIT-6-Co₃O₄），并通过真空抽滤法将其与普通商用隔膜Celgard 2500复合，后续对KIT-6-Co₃O₄复合层的厚度进行了有效调控，制备得到三种不同厚度的复合隔膜，分别应用于锂硫电池以探索其改善电池性能的效果。电化学性能测试结果表明，与未修饰改性的Celgard 2500隔膜相比，通过真空抽滤法制备出的三种复合隔膜中，KIT-6-Co₃O₄颗粒分散均匀且厚度最薄的复合隔膜（即0.002g介孔Co₃O₄附着的隔膜，记为KIT-6-Co-2）具有最宽的电化学稳定窗口，应用于锂硫电池后展示出最佳的电化学性能。在0.2 C的电流密度下进行恒电流充放电测试，其首圈放电比容量达到996.16 mAh·g^-1，在循环50圈后，仍维持有550mAh·g^-1，此工作可对锂硫电池的隔膜改性提供新的思路。

As the global economy continues to develop and the demand for energy increases, the research and development process of battery energy storage systems has been given a strong impetus, and research on energy storage systems such as lithium-ion batteries, lithium-sulphur batteries and non-lithium metal batteries has been on the rise. Among these energy storage systems, lithium-sulfur batteries have received widespread attention from scholars due to their high energy density, easy availability of raw materials and eco-friendliness. However, as the research on lithium-sulphur batteries continues, their inherent shortcomings have gradually emerged, such as the low utilisation of the active material sulphur, poor electron conduction, the "shuttle effect" caused by the high solubility of intermediate products and the volume expansion of sulphur before and after charging and discharging, all of which seriously limit their development.
To overcome these disadvantages, especially the shuttle effect of lithium polysulphide, much research has been devoted to the design and synthesis of new sulphur host materials to improve sulphur utilisation, as well as to the optimisation of electrolytes and modification of separators, and the protection of lithium cathodes, which are also very popular areas. Among these optimisation approaches, the inhibition of polysulphide migration in the electrolyte by covering the conventional commercial separators’ surface with a functional material towards the positive side has proven to be an effective separator modification method. Further studies have shown that transition metal oxides are susceptible to chemisorption of polysulphides via Lewis acid-base interaction, therefore in this article mesoporous Co3O4 particles are used as a functional coating material to modify the separator to enhance the performance of lithium-sulphur batteries.
In this article, a mesoporous Co3O4 (KIT-6-Co3O4) with a three-dimensional pore structure was prepared by the hard stencil method and laminated with a common commercial separator, Celgard 2500, by vacuum filtration. The results of the electrochemical performance tests showed that the performance of the separators is similar to that of the lithium-sulphur batteries. The results of the electrochemical performance tests show that the KIT-6-Co3O4 composite separator with uniform particle dispersion and the thinnest thickness (KIT-6-Co-2) has the widest electrochemical stability window compared to the unmodified Celgard 2500 separator and exhibits the best electrochemical performance when applied to lithium-sulphur batteries. A constant current charge/discharge test at a current density of 0.2 C resulted in a first turn discharge specific capacity of 996.16 mAh·g-1, which was maintained at 550 mAh·g-1 after 50 cycles, and this work could provide new ideas for the modification of separators for lithium-sulphur batteries.