Olivine-type cathode for rechargeable batteries: role of chelating agents
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Date
2012-11-01
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Publisher
Elsevier
Abstract
Olivine (LiCo 1/3Mn 1/3Ni 1/3PO 4) powders were synthesized at 550-600°C for 6 h in air by a sol-gel method using multiple chelating agents and used as a cathode material for rechargeable batteries. Range of chelating agents like a weak organic acid (citric acid - CA), emulsifier (triethanolamine - TEA) and non-ionic surfactant (polyvinylpyrrolidone - PVP) in sol-gel wet chemical synthesis were used. The dependence of the physicochemical properties of the olivine powders such as particle size, morphology, structural bonding and crystallinity on the chelating agent was extensively investigated. Among the chelating agents used, unique cycling behavior (75 mAh/g after 25 cycles) is observed for the PVP assisted olivine. This is due to volumetric change in trapped organic layer for first few cycles. The trapped organic species in the electrode-electrolyte interface enhances the rate of lithium ion diffusion with better capacity retention. In contrast, CA and TEA showed a gradual capacity fade of 30 and 38 mAh/g respectively after multiple cycles. The combination of all the three mixed chelating agents showed an excellent electrochemical behavior of 100 mAh/g after multiple cycles and the synergistic effect of these agents are discussed. © 2012 Elsevier Ltd.
Description
Keywords
Olivine, Sol-gel process, Synthesis, Electric conductivity, Cathodes, Materials, Coatings, Lithium ion batteries, Citric acid, Carboxylic acids, Bonding
Citation
Kandhasamy, S., Singh, P., Thurgate, S., Ionescu, M., Appadoo, D., & Minakshi, M. (2012). Olivine-type cathode for rechargeable batteries: role of chelating agents. Paper presented to the 62nd Annual Meeting of the International Society of Electrochemistry, Electrochemical Frontiers in Global Environment and Energy 11-16 September, 2011, Niigata, Japan. In Electrochimica Acta, 82, 302-308. doi:10.1016/j.electacta.2012.05.129