Multihydrogen-bond-bridged composite solid electrolytes enabling continuous Li<sup>+</sup> pathways for stable solid-state lithium batteries.

Jia, Xin; Da, Xinyu; Qin, Yanyang; Ouyang, Yuxin; Zhao, Yuanjun; Li, Na; Chen, Jing; Ding, Shujiang · Sci Adv · 2026

basic_science · Level V

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Abstract

Composite solid electrolytes (CSEs) hold great promise for advancing safer and higher-energy-density solid-state batteries. However, the poor interface compatibility caused by the lithium carbonate (Li<sub>2</sub>CO<sub>3</sub>) passivation layer on the garnet-type Li<sub>6.4</sub>La<sub>3</sub>Zr<sub>1.7</sub>Ta<sub>0.3</sub>O<sub>12</sub> (LLZTO) surface leads to an inhomogeneous distribution of ceramic particles and discontinuous lithium ion (Li<sup>+</sup>) transport, especially for high-content ceramics. Herein, we chemically convert the Li<sub>2</sub>CO<sub>3</sub> layer into brushlike poly(ethylene glycol) methyl ether acrylate-<i>co</i>-2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl methacrylate (PEGMA-<i>co</i>-UPyMA) polymers. These modified ceramics (LLZTO-<i>g</i>-PEGMA-<i>co</i>-UPyMA) are integrated with a dynamic supramolecular ionic conducting polymer (DSICP) through hydrogen bond coupling, yielding a homogeneous LLZTO-<i>g</i>-PEGMA-<i>co</i>-UPyMA@DSICP CSE with continuous Li<sup>+</sup> transport pathways, even at 90 weight % ceramic loading. This CSE enables exceptional cycling stability, with Li|LiFePO<sub>4</sub> cells retaining 88.8% capacity after 2000 cycles and 4.4-volt Li|NMC811 cells maintaining 83.7% after 300 cycles. Impressively, the 1.26-ampere hour pouch cell retains 85.6% capacity after 100 cycles, demonstrating unprecedented feasibility for practical solid-state lithium batteries.