Tailoring polymer electrolyte ionic conductivity for production of low- temperature operating quasi-all-solid-state lithium metal batteries.

Li, Zhuo; Yu, Rui; Weng, Suting; Zhang, Qinghua; Wang, Xuefeng; Guo, Xin · Nat Commun · 2023

basic_science · Level V

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Abstract

The stable operation of lithium-based batteries at low temperatures is critical for applications in cold climates. However, low-temperature operations are plagued by insufficient dynamics in the bulk of the electrolyte and at electrode|electrolyte interfaces. Here, we report a quasi-solid-state polymer electrolyte with an ionic conductivity of 2.2 × 10<sup>-4</sup> S cm<sup>-1</sup> at -20 °C. The electrolyte is prepared via in situ polymerization using a 1,3,5-trioxane-based precursor. The polymer-based electrolyte enables a dual-layered solid electrolyte interphase formation on the Li metal electrode and stabilizes the LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub>-based positive electrode, thus improving interfacial charge-transfer at low temperatures. Consequently, the growth of dendrites at the lithium metal electrode is hindered, thus enabling stable Li||LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> coin and pouch cell operation even at -30 °C. In particular, we report a Li||LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> coin cell cycled at -20 °C and 20 mA g<sup>-1</sup> capable of retaining more than 75% (i.e., around 151 mAh g<sup>-1</sup>) of its first discharge capacity cycle at 30 °C and same specific current.