Toward High-Areal-Capacity Electrodes for Lithium and Sodium Ion Batteries

摘要

In recent decades, extensive nanomaterials and related techniques havebeen proposed to achieve high capacities surpassing conventional batteryelectrodes. Nevertheless, most of them show low mass loadings and arealcapacities, which deteriorates the cell-level energy densities and increasescost after the consideration of inactive components in batteries. Achievinghigh-areal-capacity is essential for those advanced materials to move outof laboratories and into practical applications, yet remains challengingdue to the decreased mechanical properties and sluggish electrochemicalkinetics at elevated mass loadings. In this paper, the previously reportedstrategies for promoting areal lithium storage performance, includingmaterial-level designs, electrode-level architecture optimization, and novelmanufacturing techniques are reviewed. Sodium-ion battery electrodesare discussed subsequently, emphatically on its difference with those forlithium storage. Pouch-cell-level energy densities based on high-arealcapacityelectrodes with different thicknesses are also estimated. For eachcategory of these strategies, working principles, advantages, and possibleproblems are analyzed, with typical examples presented in detail anda summary table comparing the structures and achieved performance.Finally, the features of the high-areal-capacity electrodes demonstrated inthis review are concluded, and overlooked issues and potential researchdirections in this field are summarized.