绿色能源电池已被广泛应用于人类各方面生产生活中，小到日常生活的手机、笔记本电脑，大到生产中维持运作的储能、转换电站等都离不开绿色能源电池，锂离子二次电池因锂在地壳中含量丰富、成本较低等优点已成为近年来的发展重心。而负极材料作为锂二次电池中决定电池容量、稳定性、安全性、使用寿命的重要组成部分，开发具有高比容量、高能量密度的负极材料是目前锂离子电池材料研究发展的关键。硅基负极材料的理论比容量可以达到4200 mAh/g，但其存在巨大的体积膨胀，导致大规模商业化应用受到了限制。本文以复合化方式在硅单质材料中引入碳纳米管与MXene二维片层材料，构筑了硅基复合材料MXene/CNTs/Si作为锂电负极，在抑制硅体积膨胀的同时，提高了硅基负极材料的电化学性能。

本文基于基础体系，对纯硅纳米颗粒作负极时的锂离子电池材料的组成进行了讨论，并计算模拟了硅单胞结构对Li⁺嵌入的体积变化。研究发现纯硅负极嵌锂时体积膨胀明显，但是具有较小粒径的纳米硅颗粒、以羧甲基纤维素钠为粘结剂、含有5%氟代碳酸乙烯酯添加的LiPF₆电解液组成的锂离子电池具有较小的内阻、较优的循环稳定性以及倍率性能。电池材料组成的选择一定程度上优化了纯硅负极在充放电过程中产生的体积膨胀、容量损失。

在上述研究基础上又对硅单质与碳纳米管不同配比、不同合成方式进行了探讨。最佳配比、最优合成方法制备的硅碳纳米管复合材料循环性能优异、倍率性能高，较纯硅负极材料的电化学性能提升显著。碳纳米管将硅纳米颗粒包裹、穿插，有效减小了纯硅负极的体积膨胀及较差的导电性。

通过一系列层层递进的实验，将合成方法、最优配比的硅碳纳米管复合材料通过超声、抽滤的方法与MXene进行复合，成功制备了“三明治”型的MXene/CNTs/Si复合薄膜柔性材料。三维层状结构有利于限制硅的体积膨胀，也为缩短锂离子的传输路径提供了通道，该材料可直接作为锂离子电池负极，提高了电极材料活性物质的利用率，使硅基碳纳米管MXene复合材料具有更优异的电化学性能。

Green energy batteries have been widely used in all aspects of human production and life, from mobile phones and laptops in daily life to energy storage and conversion power stations that maintain operation in production. Green energy batteries are inseparable from lithium-ion secondary batteries have become the center of development in recent years due to the rich content of lithium in the earth's crust and the low cost. As the anode materials are an important part of the lithium secondary battery that determines the battery capacity, stability, safety, and service life, the development of anode materials with high specific capacity and high energy density is the key to the current research and development of lithium ion battery materials. The theoretical specific capacity of the silicon-based anode materials can reach 4200 mAh/g, but its huge volume expansion has limited its large-scale commercial applications. In this paper, carbon nanotubes and MXene, two-dimensional sheet materials, are introduced into silicon elemental materials, and the silicon-based composite material MXene/CNTs/Si is constructed as lithium battery anodes. While suppressing the volume expansion of silicon, the electrochemical properties of the silicon-based anode materials are improved.

In this paper discussed the composition of lithium-ion battery materials when pure silicon nanoparticles were used as the negative electrodes, calculated and simulated the volume change of the silicon unit cell structure to Li⁺ insertion. The study found that the volume expansion of pure silicon negative electrodes are obvious when lithium is inserted. And it composed of nano silicon particles with smaller particle size, sodium carboxymethyl cellulose as binder, and LiPF₆ electrolyte containing 5% fluoroethylene carbonate, lithium-ion batteries have smaller internal resistances, better cycle stabilities and rate performances. The selection of battery materials composition optimizes to a certain extent the volume expansion and capacity loss of pure silicon anodes during charge and discharge.

On the basis of the above research, the different ratios and different synthesis methods of silicon element and carbon nanotubes were discussed. The silicon-carbon nanotube composites prepared by the best ratio and the best synthesis method has excellent cycle performance and high rate performance, and the electrochemical performance of the pure silicon anode materials are significantly improved. Carbon nanotubes wrap and intersperse silicon nanoparticles, which effectively reduces the volume expansion and poor conductivity of pure silicon anodes.

Through a series of progressive experiments, the synthesis method and optimal ratio of silicon carbon nanotubes composite materials were combined with MXene by ultrasonic and vacuum filtration methods, and the "sandwich" type MXene/CNTs/Si were successfully prepared,which are film flexible composite materials. The three-dimensional layered structure is conducive to limiting the volume expansion of silicon, and also provides a channel for shortening the transmission path of lithium ions. The materials can be directly used as the anode electrodes of lithium-ion batteries, which improves the utilization rate of the active materials of the electrode materials and makes the silicon-based carbon nanotubes MXene composite materials have more excellent electrochemical properties.