Inorganic-polymer composite electrolytes: basics, fabrications, challenges and future perspectives

Abstract This review covers the basics of, inorganic-polymer composite electrolyte materials that combine inorganic components with polymer matrices to enhance the ionic conductivity and mechanical properties of the electrolyte. These composite electrolytes are commonly employed in solid-state batteries, fuel cells, supercapacitors, and other electrochemical devices. The incorporation of inorganic components, such as ceramic nanoparticles or metal oxides, into a polymer matrix provides several advantages. The inorganic components can improve the overall ionic conductivity by providing pathways for ion transport, reducing the tortuosity of the polymer matrix, and facilitating ion hopping between polymer chains. Additionally, inorganic materials often exhibit higher thermal and chemical stability compared to pure polymers, which can enhance the safety and durability of composite electrolytes. Polymer matrices used in inorganic-polymer composite electrolytes can vary, but common choices include polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), and polyethylene oxide/polypropylene oxide (PEO/PPO) blends. These polymers offer good mechanical flexibility and processability, allowing for the fabrication of thin films or membranes. The fabrication methods for inorganic-polymer composite electrolytes depend on the specific application and desired properties. Common approaches include solution casting, in situ polymerization, melt blending, and electrospinning. During the fabrication process, the inorganic components are typically dispersed or mixed with the polymer matrix, and the resulting composite is processed into the desired form, such as films, membranes, or coatings. The performance of inorganic-polymer composite electrolytes is evaluated based on their ionic conductivity, mechanical strength, electrochemical stability, and compatibility with the electrode materials. Researchers continue to explore various combinations of inorganic and polymer components, as well as optimization strategies, to further improve the overall performance of these composite electrolytes for advanced energy storage and conversion applications.