磷化物/石墨烯的设计构筑及储钠性能研究

Sodium-ion batteries (SIBs) posses more promising applications in grid-scale electric energy storage system compared with lithium-ion batteries (LIBs) due to its low-cost of the devices. However, designing and fabricating new high specific capacity electrode materials are still the main challenges faced by the SIBs before their practical applications, which are also the key issues to facilitate the fast development of SIBs with high specific capacity, long cycle life and excellent rate performance. Recently, Phosphorus (P)-based composites have received tremendous attentions due to their high theory specific capacity as anode materials for SIBs. This project is mainly focused on the development of novel nanostructured anode materials for the next-generation energy-storage and power Na-ion batteries. The hybrid nanostructures comprising P-based composite and graphene with stable structure will be controllably fabricated, and will be used as anode materials with high specific capapcity, long cycle life, and high rate capability. The controlled growth and formation mechanism of the nanostructures and nanoarchitectured assemblies will be explored. The dependence of the capacity, rate capability, and cycle life on the component, structure, morphology of the hybrids will be investigated systematically. The synergistic effect of the building blocks will be explored on the base of both the experimental and the theoretical results. The relationship between the microstructure/nanostructure and the sodium ions storage performance together with the evolution rules will be clarified. Furthermore, we will explore the processes of the electron conduction and Na-ion diffusion during the discharge and charge reactions, facilitating the controlled synthesis and future use of the high-performance anode materials for NIBs. It is expected that this research would not only provide beneficial guidance and help to the next-generation high-performance SIBs, but also build the fundamental scientific foundations for developing advanced energy transfer and storage systems, thus promoting the discipline cross and fusion of physics, materials, chemistry, and energy.

钠离子电池，由于价格低廉，相比于锂离子电池在大规模储能领域具有更大的应用前景。然而，构筑新的高容量的正负电极材料是钠离子电池实际应用的巨大挑战，也是制约高比容、长循环、高倍率性能的钠离子电池发展的关键问题。磷化物由于其高的理论容量已成为高比能钠离子电极材料的研究热点。本项目旨在研发一系列高性能钠离子电池新型负极材料，可控构筑结构稳定且具有高能量密度的磷化物/石墨烯的纳米复合材料。探索纳米结构与纳米组装体的可控生长与形成机制，系统研究纳米复合材料的组分、结构等对其比容量、倍率性能、循环寿命的影响，在实验和理论结合的基础上探究纳米构筑单元的协同效应，揭示纳米结构与储钠性能的构效关系与演变规律，探索新型电极材料在电化学反应过程中的电子传导、钠离子扩散的相关机理，实现高性能的电池材料的可控制备与应用，为开发高性能的钠离子二次电池提供有益的指导与帮助，促进物理、材料、化学、能源等学科的交叉与融合。

全球气候变化及碳达峰、碳中和目标，以及电动汽车、电动船舶及智能电网的快速发展，人类对储能技术的要求越来越高， 在过去的30多年里，锂离子电池以无可比拟的能量密度统治着全球二次电池市场，但是由于全球50%的锂资源分布在南美洲，我国80%的锂资源依靠进口，而钠元素具有与锂相似的电化学性质，在地壳储量高达2.30%，远超 Li含量，且不受地域分布限制。据最新市场调研显示，碳酸钠原材料市场价格仅为0.16～0.20万元/吨，而碳酸锂的价格高达50～60万元/吨，由此可以预见钠离子电池将极大降低储能器件的成本，因此近几年吸引了学术界和工业界不断增长的研究兴趣，由此钠离子电池的正负极材料的研究得到了快速的发展，但是负极材料的低容量限制了它的进一步应用。高比容量负极材料随之成为研究的热点，但是低成本、批量化、结构可控的微纳制备技术及新材料仍具有很大的挑战性。通过该项目的持续研究，取得一系列创新型研究成果：.（1）开展新的实验设计，发展新的制备技术，构筑了新型Sb/P分级微纳复合结构，结构优化的Sb/P@C负极材料获得了较好的电化学储钠性能，并借助电化学表征技术进一步分析了其储钠机理, 相关研究成果以“Mass produced Sb/P@C composite nanospheres for advanced sodium-ions battery anodes” 发表于国际电化学TOP期刊Electrochimica Acta（439, 2023, 141602, https: // doi. Org/10.1016/j.electacta. 2022.141602）。.（2）发展新的材料：探索新的锡锑氧化物SnSb2O5，制备了该氧化物与碳纤维的复合材料，通过温度及时间的调控，对复合材料中Sn，Sb相及数量进行有效调控，研究了不同组分的复合材料的储钠特性，探讨了纳米组装单元的协同储钠效应，相关研究成果以“High-capacity Sb2SbO5 with controlled Sb/Sn phase modulation as advanced anode material for sodium-ion batteries” 发表于国际期刊 Journal of Alloys and Compounds (938, 2023, 168472, https://doi.org