Li Yanpeng, Zhang Yi, Li Zhen, Yan Zhijun, Xiao Xiangpeng, Liu Xueting, Chen Jie, Shen Yue, Sun Qizhen, Huang Yunhui
School of Optical and Electronic Information, National Engineering Research Center of Next Generation Internet Access-system, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
Adv Sci (Weinh). 2022 Sep;9(26):e2203247. doi: 10.1002/advs.202203247. Epub 2022 Jul 21.
With zero excess lithium, anode-free lithium metal batteries (AFLMBs) can deliver much higher energy density than that of traditional lithium metal batteries. However, AFLMBs are prone to suffer from rapid capacity loss and short life. Monitoring and analyzing the capacity decay of AFLMBs are of great importance for their future applications. It is known that the capacity fade mainly comes from the formation of solid electrolyte interphase species and dead lithium, which leads to irreversible volume expansion. Therefore, monitoring and distinguishing the irreversible volume expansion or reversible volume expansion are the key points to analyze the capacity fade of AFLMBs. Herein, an applicable technique based on optical fiber sensors to characterize and quantize the volume change of AFLMBs is developed. By attaching fiber Bragg grating (FBG) sensors onto the surface of the multilayered anode-free pouch cells, the strain evolution of the cells is successfully monitored and correlated with their electrochemical properties. It is found that the decline of surface strain fluctuation amplitude caused by the loss of active lithium is the leading indicator of battery failure. The proposed sensing technique has excellent multiplexing capability that can be considered as an elementary unit for capacity fade analysis in next-generation battery management system.
在无过量锂的情况下，无阳极锂金属电池（AFLMBs）能够提供比传统锂金属电池更高的能量密度。然而，AFLMBs容易出现快速的容量损失和较短的寿命。监测和分析AFLMBs的容量衰减对于它们未来的应用至关重要。众所周知，容量衰减主要源于固体电解质界面物种和死锂的形成，这会导致不可逆的体积膨胀。因此，监测和区分不可逆体积膨胀或可逆体积膨胀是分析AFLMBs容量衰减的关键要点。在此，开发了一种基于光纤传感器的适用技术，用于表征和量化AFLMBs的体积变化。通过将光纤布拉格光栅（FBG）传感器附着在多层无阳极软包电池的表面，成功监测了电池的应变演变，并将其与电化学性质相关联。研究发现，由活性锂损失引起的表面应变波动幅度的下降是电池失效的主要指标。所提出的传感技术具有出色的复用能力，可被视为下一代电池管理系统中容量衰减分析的基本单元。
