摘要
近年来,随着可穿戴和便携式产品的快速发展,对柔性电子设备的需求日益增加。柔性电池作为其关键部件,得到了越来越多的研究和关注,开发具有高能量密度的柔性电池,对柔性电子设备的未来发展意义重大。锂硫电池具有较高的理论容量和能量密度,且成本低廉,是未来储能领域发展的重要前沿方向。因此,开发高性能的柔性锂硫电池更能满足未来柔性可穿戴电子器件的需求。但是,传统锂硫电池很难实现较高的柔韧性,因为其电极材料多为刚性材料,不易或不能弯曲;电解液为液态,弯曲过程中,容易发生泄漏;电池结构多为传统物理组装,材料界面结合较差。电池弯曲变形后,将丧失原有性能,或发生性能的快速衰退。鉴于此,适用于柔性锂硫电池的电极材料、固态电解质的开发及电池结构设计创新成为国内外学者研究的热点。目前,柔性电极主要采用碳纳米管、石墨烯、碳布、碳纸等碳基材料或高分子材料,在此基础上的改性材料也被广泛应用。这些材料不仅可满足设备对于机械柔性的要求,同时其多孔及大比表面积等性质有助于离子快速的迁移及界面阻抗的降低等,提高了电池整体性能。固态电解质则多采用凝胶电解质、聚合物固态电解质及无机固态电解质,其化学稳定性优良,安全性高,具有较好的柔性和可塑性。同时,根据拓扑原理,可以设计新的电池结构,如纸张叠层型、线缆型、可编织型等,降低形变过程中电池内部结构的应力变化,以满足电池的柔性要求。本文从电极材料、固态电解质及电池结构设计三方面阐述了锂硫电池柔性化研究的相关成果,分析探讨了面临的问题及未来发展方向。
In recent years,demand for flexible electronic devices has been constantly growing with the rapid emergence of wearable and portable devices. Flexible batteries as the key components have attracted great research interests. It is most critical to develop batteries with higher energy-density for the future development of flexible electronic devices.Lithium-sulfur( Li-S) batteries are considered to be important frontier of energy storage in the future due to their high theoretical capacity,high energy density and low cost. Thus,the development of high-performance flexible lithium-sulfur batteries can meet better the increasing needs of future flexible wearable electronic devices. However,traditional lithium-sulfur batteries are difficult to achieve high flexibility: the rigid electrode material cannot be bended easily;the liquid electrolytes raise the risk of electrolyte leakage under bending state;poor interfacial contact owing to the assembly method based on physical joining. Once subjected to bending or stretching,traditional lithium-sulfur batteries will lose its function or undergo fast performance decline. Therefore,considerable efforts have been made in these years focusing on developing electrode materials and solid-state electrolytes which are adaptable for flexible batteries,as well as on creating special battery structures.Currently,flexible electrode materials are mainly based on carbon or its modified materials,such as carbon nanotubes,graphene,carbon cloth and carbon paper,as well as polymer materials. These materials not only can meet the flexible requirements,but also are beneficial for the overall battery performance through strengthening Li+/electrons transportation and reducing interface impedance due to the porous structure and the large specific surface. Solid-state electrolytes which contains gel polymer electrolytes,polymer electrolytes and inorganic electrolytes,has good chemical stability,high safety,high flexibility and plasticity. At the same time,the novel battery structure design,such as linear structure,paper folding structure and braided structure have been realized according to the topology principle,through which can the stress change of the battery internal structure during deformation process be reduced.This review gives a summary of relevant achievements in the flexibilization of lithium-sulfur batteries from the perspectives of electrode materials,solid-state electrolytes,and battery structure design. It also includes a prospective discussion upon the challenges and future development trends.
作者
刘建伟
王嘉楠
朱蕾
延卫
LIU Jianwei;WANG Jianan;ZHU Lei;YAN Wei(Department of Environmental Science and Engineering,Xi’an Jiaotong University,Xi'an 710049,China;Department of Applied Chemistry,School of Science,Xi’an Jiaotong University,Xi'an 710049,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2020年第1期155-168,共14页
Materials Reports
基金
国家自然科学基金(51978569)
国家自然科学基金青年项目(51803164)
中国博士后基金(2018M643635)
陕西省自然科学基金(2019JQ-126)~~
关键词
柔性
锂硫电池
电极材料
固态电解质
结构设计
flexibility
lithium-sulfur battery
electrode material
solid-state electrolyte
structural design