Bamford James T, Jones Seamus D, Schauser Nicole S, Pedretti Benjamin J, Gordon Leo W, Lynd Nathaniel A, Clément Raphaële J, Segalman Rachel A
Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States.
Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106, United States.
ACS Macro Lett. 2024 May 21;13(5):638-643. doi: 10.1021/acsmacrolett.4c00158. Epub 2024 May 6.
Next-generation batteries demand solid polymer electrolytes (SPEs) with rapid ion transport and robust mechanical properties. However, many SPEs with liquid-like Li transport mechanisms suffer a fundamental trade-off between conductivity and strength. Dynamic polymer networks can improve bulk mechanics with minimal impact to segmental relaxation or ionic conductivity. This study demonstrates a system where a single polymer-bound ligand simultaneously dissociates Li and forms long-lived Ni networks. The polymer comprises an ethylene oxide backbone and imidazole (Im) ligands, blended with Li and Ni salts. Ni-Im dynamic cross-links result in the formation of a rubbery plateau resulting in, consequently, storage modulus improvement by a factor of 133× with the introduction of Ni at = 0.08, from 0.014 to 1.907 MPa. Even with Ni loading, the high Li conductivity of 3.7 × 10 S/cm is retained at 90 °C. This work demonstrates that decoupling of ion transport and bulk mechanics can be readily achieved by the addition of multivalent metal cations to polymers with chelating ligands.
下一代电池需要具有快速离子传输和强大机械性能的固体聚合物电解质（SPEs）。然而，许多具有类似液体锂传输机制的SPEs在电导率和强度之间存在根本的权衡。动态聚合物网络可以在对链段弛豫或离子电导率影响最小的情况下改善整体力学性能。本研究展示了一种体系，其中单个聚合物结合配体同时离解锂并形成长寿命的镍网络。该聚合物由环氧乙烷主链和咪唑（Im）配体组成，与锂盐和镍盐混合。镍-咪唑动态交联导致形成橡胶状平台，因此，在镍含量为0.08时，储能模量提高了133倍，从0.014 MPa提高到1.907 MPa。即使有镍负载，在90°C时仍保持3.7×10 S/cm的高锂电导率。这项工作表明，通过向具有螯合配体的聚合物中添加多价金属阳离子，可以很容易地实现离子传输和整体力学性能的解耦。
