Commercialized lithium-ion batteries (LIBs) with a liquid electrolyte have a high potential for combustion or explosion. The use of solid electrolytes in LIBs is a promising way to overcome the drawbacks of conventional liquid electrolyte-based systems, but they generally have a lower ionic conductivity and lithium ion mobility. Here, a UV-crosslinked composite polymer-clay electrolyte (U-CPCE) that is composed of a durable semi-interpenetrating polymer network (semi-IPN) ion transportive matrix (ETPTA/PVdF-HFP) and 2D ultrathin clay nanosheets that are fabricated by a one-step in situ UV curing method, are reported. The U-CPCE exhibits robust and flexible properties with an ionic conductivity of more than 10−3 S cm−1 at room temperature with the help of exfoliated clay nanosheets. As a result, the U-CPCE-based LIBs show an initial discharge capacity of 152 mAh g−1 (at 0.2 C for a LiCoO2 half-cell), which is comparable to that of conventional liquid electrolyte-based cells. In addition, they show excellent cycling performance (96% capacity retention after 200 cycles at 0.5 C) due to a significantly enhanced Li+ transference number (tLi+ = 0.78) and inhibition of lithium dendrite formation on the lithium metal surface. Furthermore, a molecular dynamics (MD) study is conducted to elucidate the mechanism of improving ionic conductivity. The U-CPCE design can offer opportunities for future all-solid-state Li-ion batteries.
Bibliographical noteFunding Information:
This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT and Future Planning (2018M3D1A1058624, 2018M1A3A3A02065974, 2019R1A2C3010479).
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All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)