Kang Ben-Hao, Li Shuang-Feng, Yang Jinlong, Li Zhong-Ming, Huang Yan-Fei
College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
ACS Nano. 2023 Jul 25;17(14):14114-14122. doi: 10.1021/acsnano.3c04684. Epub 2023 Jul 5.
Conventional polymer/ceramic composite solid-state electrolytes (CPEs) have limitations in inhibiting lithium dendrite growth and fail to meet the contradictory requirements of anodes and cathodes. Herein, an asymmetrical poly(vinylidene fluoride) (PVDF)-PbZrTiO (PZT) CPE was prepared. The CPE incorporates high dielectric PZT nanoparticles, which enrich a dense thin layer on the anode side, making their dipole ends strongly electronegative. This attracts lithium ions (Li) at the PVDF-PZT interface to transport through dipolar channels and promotes the dissociation of lithium salts into free Li. Consequently, the CPE enables homogeneous lithium plating and suppresses dendrite growth. Meanwhile, the PVDF-enriched region at the cathode side ensures intermediate contact with positive active materials. Therefore, Li/PVDF-PZT CPE/Li symmetrical cells exhibit a stable cycling performance exceeding 1900 h at 0.1 mA cm at 25 °C, outperforming Li/PVDF solid-state electrolyte/Li cells that fail after 120 h. The LiNiCoMoO/PVDF-PZT CPE/Li cells show low interfacial impedances and maintain stable cycling performance for 500 cycles with a capacity retention of 86.2% at 0.5 C and 25 °C. This study introduces a strategy utilizing dielectric ceramics to construct dipolar channels, providing a uniform Li transport mechanism and inhibiting dendrite growth.
传统的聚合物/陶瓷复合固态电解质（CPEs）在抑制锂枝晶生长方面存在局限性，无法满足阳极和阴极相互矛盾的要求。在此，制备了一种不对称的聚偏氟乙烯（PVDF）-锆钛酸铅（PZT）CPE。该CPE包含高介电常数的PZT纳米颗粒，这些纳米颗粒在阳极侧富集形成致密的薄层，使其偶极端具有强电负性。这吸引了PVDF-PZT界面处的锂离子（Li）通过偶极通道传输，并促进锂盐解离成游离的Li。因此，该CPE能够实现均匀的锂沉积并抑制枝晶生长。同时，阴极侧富含PVDF的区域确保了与正极活性材料的中间接触。因此，Li/PVDF-PZT CPE/Li对称电池在25℃下以0.1 mA cm的电流密度表现出超过1900 h的稳定循环性能，优于120 h后就失效的Li/PVDF固态电解质/Li电池。LiNiCoMoO/PVDF-PZT CPE/Li电池显示出低界面阻抗，并在25℃下以0.5 C的电流密度保持500次循环的稳定循环性能，容量保持率为86.2%。本研究介绍了一种利用介电陶瓷构建偶极通道的策略，提供了一种均匀的Li传输机制并抑制枝晶生长。
