A review of composite organic-inorganic electrolytes for lithium batteries

To address the challenges of energy storage technologies, researchers have developed organic-inorganic composite solid electrolytes (CSEs) that integrate the advantages of both inorganic solid electrolytes and polymer materials, and show excellent mechanical, safety and reliability performance, which have become one of the most prevalent electrolyte system. Nevertheless, some issues remain unresolved, including the limited ionic conductivity, the occurrence of lithium dendrites, and the instability of the solid-solid interface. In this article, we provided a summary of three key approaches to improve the performance of CSEs: (i) Surface treatment, concentration adjustment, and morphology and size tailoring of filler to increase ionic conductivity, (ii) Introducing 3D scaffolds and constructing optimal space charge layer to inhibit lithium dendrite growth, (iii) Designing multilayer composite CSEs to achieve good interface matching between CSEs and electrodes, and utilizing chemical interactions between fillers and polymer matrix to improve interface stability and affinity. At the same time, introducing additives and constructing a three-dimensional structure can reduce interface impedance and improve battery performance. This review also prospects the development trends and challenges of CSEs. This article summarizes the performance optimization methods of solid-state electrolytes (CSEs) from three key areas: ionic conductivity, lithium dendrite formation, and interface stability. [Display omitted] •The performance optimization methods of solid-state electrolytes were summarized from three aspects.•The pros and cons of different solid electrolytes were analyzed.•The challenges faced by CSEs in terms of ion conductivity were mainly discussed.•The development trends and challenges of CSE were predicted.