Reversible Switching of Battery Internal Resistance Using Iongate Separators |
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Authors: | Matthew S Gonzalez Qizhang Yan John Holoubek Mingqian Li Zhaohui Wu Hongyao Zhou Sean Kim Haodong Liu Bum-Young Jung Suk-woo Lee Zheng Chen Ping Liu |
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Affiliation: | 1. Department of Nanoengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093 USA;2. LG Energy Solution Research Park, 188, Munji-ro, Yuseong-gu, Daejeon, 305-738 Republic of Korea |
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Abstract: | Battery separators are a critical component that greatly determine cell calendar life and safety. Generally, these separators are passive with no ability to reversibly change their properties in order to optimize battery performance. Here, an iongate separator is demonstrated, which allows ion transport while in the oxidized “on” state but limits ion transport when switched to the reduced “off” state. This is achieved by depositing a dense 300 nm thin film of polypyrrole:polydopamine (PPy:PDA) on a conventional polyolefin separator. By using this iongate separator as a third electrode, a rapid and reversible order of magnitude increase of iongate resistance is achievable. The iongate battery shows similar cycling performance to a normal battery while in the “on” state, but cycling can be reversibly shut-off when the iongate separator is reduced to the “off” state. During elevated temperature storage with the iongate separator in the “off” state, battery capacity loss is decreased by 37% and transition metal crossover is greatly suppressed when compared to a normal battery without the iongate. Additionally, rapid shut-off during discharge is demonstrated by directly shorting the iongate separator to the anode. |
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Keywords: | battery safety battery shut-off battery storage iongate separators smart separators |
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