高エネルギー全固体リチウム電池向け高分子―可塑剤非相溶問題を克服 (Scientists Overcome Polymer-Plasticizer Incompatibility for High-Energy Solid-State Lithium Batteries)

2026-05-21 中国科学院(CAS)

中国科学院金属研究所(IMR)の研究チームは、高エネルギー・高安全性の全固体リチウム金属電池実用化に向け、ポリマー電解質と可塑剤の相溶性問題を解決する新たな「相溶化溶媒可塑化戦略」を開発した。従来、PVDF系ポリマー電解質は高い酸化安定性とイオン伝導性を持つ一方、一般的可塑剤は電極界面で分解しやすく、逆に安定なスルホラン系可塑剤はPVDFと熱力学的に相溶せず均一膜形成が困難だった。研究チームは揮発性の相溶化溶媒を導入することで混合系の相互作用を制御し、均一な前駆体溶液形成に成功した。さらに蒸発過程でスルホランを三次元ポリマー網目内に固定化し、安定な電解質膜を実現した。得られた全固体電池は4.7V高ニッケル正極との組み合わせで20Cの超高速充放電条件下でも700サイクル安定動作し、容量保持率81.9%を達成。エネルギー密度451.5Wh/kgの大型パウチセルでも高安全性を示し、釘刺し試験にも耐えた。研究成果は2026年5月21日付『Journal of the American Chemical Society』誌に掲載された。

<関連情報>

Polymer-Modulated Solvation Chemistry via Compatibilizing-Solvent Plasticization for Stable High-Energy Lithium Metal Batteries

Ruogu Xu,Yujie WangShengjun XuJiawei ShiYuxuan FengYukun YanZhuangnan LiChunyang WangYun TianShuo BaiHui-Ming ChengZhenhua Sunand Feng Li
Journal of the American Chemical Society  Published: May 19, 2026
DOI:https://doi.org/10.1021/jacs.6c02800

Abstract

高エネルギー全固体リチウム電池向け高分子―可塑剤非相溶問題を克服 (Scientists Overcome Polymer-Plasticizer Incompatibility for High-Energy Solid-State Lithium Batteries)

Poly(vinylidene fluoride) (PVDF)-based polymer electrolytes plasticized with residual solvent are promising for high-energy and high-safety lithium metal batteries. However, their practical realization is constrained by the reliance on miscible yet electrochemically unstable plasticizers (such as N,N-dimethylformamide), which compromise both lithium reversibility and high-voltage compatibility. Guided by a descriptor-informed screening, we identify several electrochemically favorable plasticizers, but their thermodynamic immiscibility with polymers precludes homogeneous plasticization. Here, we propose a compatibilizing-solvent-enabled plasticization strategy that leverages a transient solvent to lower the effective Flory–Huggins interaction parameter, thereby enabling the homogeneous plasticization of poly(vinylidene fluoride-co-hexafluoropropylene) with immiscible plasticizers. Using sulfolane as a representative plasticizer, the resulting polymer–sulfolane (Fδ−–Hδ+) interactions suppress sulfolane migration and modulate an anion-aggregate solvation structure, leading to anion-derived fluorine-rich solid–electrolyte interphases. Consequently, the polymer electrolyte delivers an average lithium plating/stripping Coulombic efficiency of 99.1% over 1400 cycles, supports stable cycling of 4.7 V Ni-rich cathodes at 20C (7.1 mA cm–2), and achieves an energy density of 451.5 Wh kg–1 in Ah-scale pouch cells. More broadly, this work establishes a general route for expanding the plasticizer design space of PVDF-based polymer electrolytes, offering a promising direction toward practical lithium metal batteries.

0504高分子製品
ad
ad
Follow
ad
タイトルとURLをコピーしました