聚異戊二烯-磺酸化異戊二烯雙嵌段共聚高分子及其於固態電解質之應用

固態電解質在應用上無需添加電解液，及其具有抑制鋰金屬枝晶成長的特色，因此被視為擁有提升鋰電池安全性與穩定性的潛力。然而，固態電解質面臨最大的問題為室溫的離子傳導度低。本研究透過陰離子聚合法及後續的官能基修飾，開發出具有不同組成比例的聚異戊二烯–磺酸化異戊二烯（II）雙嵌段共聚高分子電解質，以作為非多孔性固態電解質薄膜，其在30 °C時的離子傳導度可以達到1.49×〖10〗^(-5) S cm-1。另外，引入不同重量比例之具有鋰離子傳導性的LLZO陶瓷粒子至II基材中，並透過溶劑揮發法成膜，可製備得厚度介於50~80 μm的II-LLZO複合固態電解質薄膜。本研究發現，當II中具有較高比例之PI(1,4)軟鏈段，可提升LLZO引入重量比例增加時其複合固態電解質薄膜的成膜性及表面平整度。II的組成比例與II-LLZO複合固態電解質的微結構會影響LLZO引入重量比例之於離子傳導度的關係。

關鍵字

陰離子聚合法；雙嵌段共聚高分子；聚電解質；固態電解質； LLZO ；複合固態電解質

並列摘要

Solid-state electrolytes offering great potential to solve safety and stability issues of lithium batteries by avoiding the use of liquid electrolytes and by suppressing the lithium dendrite growth. However, the low ionic conductivity at room temperature of solid-state electrolytes severely challenges their further success. In this work, we designed and synthesized poly(isoprene-block-sulfonated isoprene) (II) diblock polyelectrolytes with different compositions and fabricated the corresponding non-porous membranes to serve as solid-state electrolytes (SE). II diblock polyelectrolytes were prepared from anionic polymerization with the following analogous chemistry. An ionic conductivity of 1.49×〖10〗^(-5) S cm-1 at 30 °C could be achieved. We also introduced different amount of lithium-ion conducting LLZO particles to II matrix, and II-LLZO composite solid-state electrolyte (CSE) membranes with thickness around 50~80μm were obtained via solvent casting. It is found that the higher flexible PI(1,4) content of II could offer the resulting CSE better membrane quality with smooth surfaces upon increasing LLZO content. The effect of the loading amount of LLZO on the ionic conductivity is complicated, which depends on the composition of II and the microstructure of II-LLZO CSE.

並列關鍵字

anionic polymerization ； diblock copolymer ； polyelectrolyte ； solid-state electrolyte ； LLZO ； composite solid-state electrolyte

參考文獻

[1] Xu, K., "Nonaqueous Liquid Electrolytes for Lithium-based Rechargeable Batteries." Chemical Reviews 2004, 104 (10), 4303-4418.

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