REVIEW

Interfacial engineering of hollow multishelled structure for metal-air batteries: Reaction mechanism and material design

¹ State Key Laboratory of Biopharmaceutical Preparation and Delivery, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
² University of Chinese Academy of Sciences, Beijing 100049, China
³ College of Chemistry and Environment Engineering, Shenzhen University, Shenzhen 518060, China

^* Corresponding authors (emails: This email address is being protected from spambots. You need JavaScript enabled to view it. (Jiawei Wan); This email address is being protected from spambots. You need JavaScript enabled to view it. (Ranbo Yu); This email address is being protected from spambots. You need JavaScript enabled to view it. (Dan Wang))

Received: 2 March 2026
Revised: 9 April 2026
Accepted: 15 April 2026

Abstract

Metal-air batteries (MABs) possess high theoretical energy density, but their practical applications are often restricted by unstable multiphase interfaces as well as mismatched mass transport and reaction kinetics. This review first outlines the operating principles of non-aqueous, aqueous, and solid-state MABs, highlights their key differences, and then summarizes the evolution characteristics of major interfaces during cycling, including the metal anode/electrolyte interface, the air cathode/electrolyte interface, and separator/electrolyte contact interfaces. The typical problems encountered in MABs include pore blockage caused by product accumulation, which reduces the effective reaction area of the cathode; increased resistance resulting from electrolyte decomposition and side reactions; anode corrosion or passivation accompanied by non-uniform deposition; and contact degradation induced by volume change and internal stress. We discuss the hollow multishelled structure (HoMS) as a potential platform, which can play roles in product buffering, transport pathway maintenance, and structural cushioning. Finally, we emphasize the importance of quantitative validation, coordinated interface design, and performance evaluation under practical working conditions, with the support of data analysis and AI tools.