Li Lin-Xin, Li Rui, Huang Zhen-Hao, Yang Hua, Liu Ming-Quan, Xiang Jun, Hussain Shahid, Shen Xiang-Qian, Jing Mao-Xiang
Institute for Advanced Materials, School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China.
School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China.
ACS Appl Mater Interfaces. 2022 Jul 13;14(27):30786-30795. doi: 10.1021/acsami.2c05578. Epub 2022 Jul 1.
Solid electrolytes with both interface compatibility and efficient ion transport have been an urgent technical requirement for the practical application of solid-state lithium batteries. Herein, a multifuctional poly(1,3-dioxolane) (PDOL) electrolyte combining the gradient structure from the solid state to the gel state with the LiLaZrTaO (LLZTO) interfacial modification layer was designed, in which the "solid-to-gel" gradient structure greatly improved the electrode/electrolyte interface compatibility and ion transport, while the solid PDOL and LLZTO layers effectively improved the interface stability of the electrolyte/lithium anode and the inhibition of the lithium dendrites via their high mechanical strength and forming a stable interfacial SEI composite film. This gradient PDOL/LLZTO composite electrolyte possesses a high ionic conductivity of 2.9 × 10 S/cm with a wide electrochemical window up to 4.9 V vs Li/Li. Compared with the pristine PDOL electrolyte and PDOL solid electrolyte membrane coated with a layer of LLZTO, the gradient PDOL/LLZTO composite electrolyte shows better electrode/electrolyte interfacial compatibility, lower interface impedance, and smaller polarization, resulting in enhanced rate and cycle performances. The NCM622/PDOL-LLZTO/Li battery can be stably cycled 200 times at 0.3C and 25 °C. This multifunctional gradient structure design will promote the development of high-performance solid electrolytes and is expected to be widely used in solid-state lithium batteries.
对于固态锂电池的实际应用而言，兼具界面兼容性和高效离子传输能力的固体电解质一直是一项迫切的技术需求。在此，设计了一种多功能聚（1,3 - 二氧戊环）（PDOL）电解质，其结合了从固态到凝胶态的梯度结构以及LiLaZrTaO（LLZTO）界面改性层。其中，“固态到凝胶”的梯度结构极大地改善了电极/电解质界面兼容性和离子传输，而固态PDOL层和LLZTO层通过其高机械强度并形成稳定的界面SEI复合膜，有效提高了电解质/锂负极的界面稳定性以及对锂枝晶的抑制作用。这种梯度PDOL/LLZTO复合电解质具有2.9×10 S/cm的高离子电导率，相对于Li/Li的宽电化学窗口高达4.9 V。与原始PDOL电解质和涂覆有一层LLZTO的PDOL固体电解质膜相比，梯度PDOL/LLZTO复合电解质表现出更好的电极/电解质界面兼容性、更低的界面阻抗和更小的极化，从而提高了倍率性能和循环性能。NCM622/PDOL - LLZTO/Li电池在0.3C和25℃下可稳定循环200次。这种多功能梯度结构设计将推动高性能固体电解质的发展，并有望在固态锂电池中得到广泛应用。
