Cyclic stability is the ability of an electrode, a device or a material to retain its performance over repeated charge-discharge or load-unload cycles, and it is reported as the fraction of the initial capacity or property remaining after a stated number of cycles at a stated rate. In batteries the loss is rarely due to one cause: the active material may transform or dissolve, the electrode may lose electrical contact as particles move apart, and the electrolyte may be consumed in side reactions that thicken the interphase. Conversion and alloying electrodes undergo the largest volume change, and embedding the active phase in a carbon matrix is the standard way to accommodate it, iron oxide in a carbon microsphere being an early example [1]. A conductive scaffold performs the same function in a silicon electrode, where a nanowire network keeps the particles connected through repeated expansion [2], and controlling the pore structure of the electrode gives the same gain more generally [3]. In lithium-sulfur cells the loss mechanism differs, because the intermediate polysulfides dissolve and migrate, so the sulfur is encapsulated in a shell [4]. Binding it into a conductive polymer network is the alternative [5]. Reported retention figures depend strongly on the rate and the depth of discharge, so they are comparable only under matched conditions.
- capacity retention
- cycle life
- volume change
- solid electrolyte interphase
- polysulfide shuttle
- electrode degradation
References
- Li, M.Y.; Wang, Y.; Liu, C.L.; Gao, H.; Dong, W.S.; Iron oxide/carbon microsphere lithium-ion battery electrode with high capacity and good cycling stability. Electrochimica Acta 2012, 67, 187-193, 10.1016/j.electacta.2012.02.015.
- Zhang, H.; Liu, S.; Yu, X.; Chen, S.; Improving rate capacity and cycling stability of Si-anode lithium ion battery by using copper nanowire as conductive additive. Journal of Alloys and Compounds 2020, 822, 153664, 10.1016/j.jallcom.2020.153664.
- Shreenivasa, L.; Yogesh, K.; Prashanth, S.A.; Viswanatha, R.; Ashoka, S.; Enhancement of cycling stability and capacity of lithium secondary battery by engineering highly porous AlV3O9. Journal of Materials Science 2020, 55, 1648-1658, 10.1007/s10853-019-04074-7.
- Xiao, M.; Huang, M.; Zeng, S.; Han, D.; Wang, S.; Sun, L.; Meng, Y.; Sulfur@graphene oxide core–shell particles as a rechargeable lithium–sulfur battery cathode material with high cycling stability and capacity. RSC Advances 2013, 3, 4914, 10.1039/c3ra00017f.
- Xiao, P.; Bu, F.; Yang, G.; Zhang, Y.; Xu, Y.; Integration of Graphene, Nano Sulfur, and Conducting Polymer into Compact, Flexible Lithium–Sulfur Battery Cathodes with Ultrahigh Volumetric Capacity and Superior Cycling Stability for Foldable Devices. Advanced Materials 2017, 29, 1703324, 10.1002/adma.201703324.