Mechanical stability is the ability of a material or a component to keep its structure, and therefore its properties, under mechanical load, deformation or repeated cycling. In electrochemical energy storage the term is taken more narrowly, for the ability of an electrode to survive the volume change that accompanies charging and discharging: active particles expand and contract, the coating swells and shrinks, and if the structure cannot accommodate the strain the coating cracks, particles lose contact with the current collector and the capacity fades. Porous and hierarchically structured electrodes accommodate that strain better than dense ones, which is why hierarchical porous carbons are reported with good rate behaviour and long life [1]. A flexible active material that deforms elastically with the substrate holds both its structure and its capacity over long cycling [2], and growing the active phase directly on a textile current collector removes the binder and the interface that usually fails first [3]. Conducting polymer composites with a two-dimensional inorganic phase combine electronic transport with mechanical compliance [4], and the same strategy has been taken into all-solid-state flexible devices where the electrode also has to survive bending [5]. Tests are rarely standardised, so cycling figures quoted under different mechanical conditions are not directly comparable.
- structural stability
- volume change
- cycling stability
- electrode coating
- crack formation
- flexible electrode
Mechanical Failure Analysis and Simulation·Mechanical Engineering·Engineering·Physical Sciences
References
- Cheng, M.; Meng, Y.; Meng, Q.; Mao, L.; Zhang, M.; Amin, K.; Ahmad, A.; Wu, S.; Wei, Z.; A hierarchical porous N-doped carbon electrode with superior rate performance and cycling stability for flexible supercapacitors. Materials Chemistry Frontiers 2018, 2, 986-992, 10.1039/c8qm00023a.
- Liu, J.; Zhao, S.; Wu, X.; Flexible electrochemical capacitor based NiMoSSe electrode material with superior cycling and structural stability. Chinese Chemical Letters 2024, 35, 109059, 10.1016/j.cclet.2023.109059.
- Feng, Y.; Shen, L.; Wang, C.; Bao, H.; Chen, N.; Lin, X.; Liu, R.; Feng, X.; Electrodeposition of NiMn-MOFs/carbon cloth for flexible all-solid-state supercapacitors electrode with ultra-long cycling stability. Electrochimica Acta 2024, 485, 144110, 10.1016/j.electacta.2024.144110.
- Ma, G.; Bai, W.; Zhou, X.; Guan, X.; Zhang, S.; Wu, W.; Li, C.; Wang, S.; Sulfonated polyaniline/MXene composite electrode with high cycling stability for anti-freezing flexible supercapacitor. Chemical Engineering Journal 2024, 496, 153730, 10.1016/j.cej.2024.153730.
- Ma, G.; Bai, W.; Zhou, X.; Yu, D.; Luo, Y.; Gao, T.; Wang, S.; Novel sulfonated polyaniline/graphene oxide electrode with high cycling stability for all-solid-state flexible supercapacitors. International Journal of Hydrogen Energy 2024, 68, 105-114, 10.1016/j.ijhydene.2024.03.326.