钠离子电池电极材料的设计策略——固态离子学视角_傅焰鹏.pdf

物 理 化 学 学 报 Acta Phys.-Chim.Sin.2023,39(3),2209002(1 of 17)Received:September 5,2022;Revised:October 18,2022;Accepted:November 2,2022;Published online:November 9,2022.*Corresponding author.Email: The project was supported by the National Natural Science Foundation of China(22075331,51702376,21905057).国家自然科学基金(22075331,51702376,21905057)资助项目 Editorial office of Acta Physico-Chimica Sinica Review doi:10.3866/PKU.WHXB202209002 Design Strategies for Sodium Electrode Materials:Solid-State Ionics Perspective Yanpeng Fu 1,Changbao Zhu 2,*1 School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China.2 School of Materials Science and Engineering,Sun-Yat Sen University,Guangzhou 510275,China.Abstract:Sodium-ion battery is one of the most promising and feasible energy storage candidates.However,compared to the lithium ion,the larger ionic radius and higher molecular mass of the sodium ion lead to inferior electrochemical performance of sodium-ion batteries.Therefore,achieving the rational design and construction of high-performance electrode materials is a key point and remains a great challenge for sodium-ion batteries.In this work,we focus on the transport properties of sodium ions and electrons and discuss design strategies of sodium electrodes from the perspective of solid-state ionics.First,for the bulk sodium electrode materials,investigating their transport properties,such as ionic conductivity,electronic conductivity,and diffusion coefficient,is a prerequisite for electrode design.Although there are various methods of measuring the diffusion coefficient,separately achieving the intrinsic ionic and electronic conductivity of the pure materials is highly important.Doping and carbon-coating are the most useful approaches to improve the specific transport properties of the investigated materials.Building defect chemistry models based on measured transport properties and relevant defect chemistry theory is crucial but remains a great challenge for the design of sodium electrodes.Second,for the nano sodium electrodes,size effects can be applied to design and construct electrodes from a nanoionics perspective.Thermodynamically,the equilibrium shape and equilibrium voltage change with a reduction in the particle size and facilitate the discovery of new electroactive electrode materials.Kinetically,according to L2/D(where is diffusion time,L is particle radius,and D is diffusion coefficient),a smaller particle size leads to better kinetic behavior(higher rate performance)and also improves the diffusion coefficient in some cases.In terms of sodium transport and storage mechanisms,size effects result in the transition from a two-phase to a single-phase mechanism,an increase in the interfacial storage and surface reaction,as well as a variation of the sodium storage mechanism in pores,further leading to variation of the discharge voltage plateau.Finally,whether for bulk or nano-electrode materials,constructing efficient electrochemical circuits by the optimization of the phases and dimensionalities based on the transport properties of electrode materials is significant in achieving the rational design of sodium electrode materials and optimizing the electrochemical performance of sodium-ion batteries.We believe that this study will serve as a useful guide for the development of sodium electrode materials and will certainly contribute to the commercialization of sodium-ion batteries.Key Words:Solid state ionics;Nano ionics;Sodium ion battery;Electrode material;Transport property;Defect chemistry;Size effect;Electrochemical circuit 物理化学学报 Acta Phys.-Chim.Sin.2023,39(3),2209002(2 of 17)钠离子电池电极材料的设计策略钠离子电池电极材料的设计策略固态离子学视角固态离子学视角 傅焰鹏1，朱昌宝2,*1广东工业大学材料与能源学院，广州 510006 2中山大学材料科学与工程学院，广州 510275 摘要：摘要：钠离子电池是目前最有前景及可行性的新兴储能候选体系。对于钠离子电池而言，如何实现其电极材料的理性设计及构筑，是重要的科学问题。本文立足于钠离子/电子输运这一核心问题，从固态离子学视角探讨钠离子电池电极材料的设计策略。首先，对于体相电极材料，输运特性的明晰、调控以及缺陷化学模型的建立，是传统电极材料开发的关键。其次，对于纳米电极材料，随着尺寸的减小，电极材料的热力学性质、动力学特性以及钠离子微观储输机制都会发生相应变化，因此从纳米离子学视角，以尺寸效应调控电极材料具有重要的科学价值及现实意义。最后，无论对于体相材料还是纳米材料，从材料的本征输运特性出发，通过电化学电路的设计和构筑来优化电极动力学，可以为钠电电极材料的理性设计及可控制备提供理论指导。我们相信，通过本文系统地对钠离子电池电极材料设计策略的梳理，必将对钠离子电池的开发，提供有意义的指导，并为最终的产业化打下良好的基础。关键词：关键词：固态离子学；纳米离子学；钠离子电池；电极材料；输运特性；缺陷化学；尺寸效应；电化学电路 中图分类号：中图分类号：O646 1 引言引言 锂离子电池是目前最成功的储能体系之一，在消费电子领域、电动汽车以及储能方面获得了广泛的应用1,2。然而由于锂储量有限、分布不均、价格昂贵，当电动汽车以及大规模储能产业发展到一定规模的时候，锂资源的稀缺性将极大的限制锂离子电池及相关产业的应用及发展3。因此，寻找可替代、廉价、高性能的新兴储能体系，具有极其重要的意义。在众多的储能体系里，钠离子电池得到人们的广泛关注，成为最有潜力的候选体系之一。从周期表来看，钠与锂处于同一主族，其物理化学性质与锂有诸多相似之处4。另外，锂离子电池研究及产业开发过程中的经验，对钠离子电池都有积极的借鉴效果。而且钠元素在地壳中储量丰富，资源分布广泛，受地域影响较小，其单质、化合物及前驱体与锂的相关资源相比，价格上优势明显。因此，这一优势使其在储能，特别是大规模储能领域展现出广阔的应用前景5。另外，从价格上来看，除了相关钠资源的价格优势外，由于钠与铝不会形成合金，所以对于钠离子电池产业来说，可以选用成本廉价的铝集流体来代替锂离子电池中的铜集流体，从而进一步降低钠离子电池的生产成本。特别值得注意的是，对于储能而言，安全性极为重要，而钠离子电池具有比锂离子电池更好的本征安全性，为其在大规模储能的应用奠定了良好的基础。综合来看，目前钠离子电池是最有前景以及最具可行性的替代锂离子电池的新兴储能候选体系。钠离子电池由正极材料、负极材料以及电解质构成。正负极材料可通过基本的氧化还原过程实现钠离子的存储，从而对外电路提供能量；而电解质的基本作用是提供自由移动的钠离子，实现电池内部的钠离子的定向输运。钠离子的正极材料一般分为层状氧化物6,7、聚阴离子材料810、普鲁士蓝类材料11以及有机电极材料12。一般来说钠离子电池正极材料会提供钠离子电池输运的通道以及存储的空间，比如一维隧道