Separators play a critical role in the safety and performance of lithium-ion batteries. However

commercial polyolefin separators are limited by their poor affinity with electrolytes and low melting points. In this work

we constructed a reinforced-concrete-like structure by homogeneously dispersing nano-Al

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and cellulose on the separators to improve their stability and performance. In this reinforced-concrete-like structure

the cellulose is a reinforcing mesh

and the nano-Al

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acts as concrete to support the separator. After constructing the reinforced-concrete-like structure

the separators exhibit good stability even at 200 ℃ (thermal shrinkage of 0.3%)

enhanced tensile strain (tensile stress of 133.4 MPa and tensile strains of 62%)

and better electrolyte wettability (a contact angle of 6.5°). Combining these advantages

the cells with nano-Al

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@cellulose-coated separators exhibit stable cycling performance and good rate performance. Therefore

the construction of the reinforced-concrete-like structure is a promising technology to promote the application of lithium-ion batteries in extreme environments.