Hollow multishelled structures revive high energy density batteries.

Hollow structures have been shown to be fruitful in addressing the cycling-stability problem of high-capacity electrode materials. However, we have noticed that there exist misconceptions toward the energy density of hollow-structured electrodes. In this Focus Article, the indispensability of hollow structures for stable high energy density batteries is discussed. Additionally, the merits of hollow multishelled structures (HoMSs) superior to their single-shelled counterparts mainly including optimizing the volumetric energy density, improving the mechanical robustness and enabling smart safe energy-storage behaviors have also been highlighted. The goal of the current article is to clarify that a HoMS-based electrode is indispensable to realize a practically high energy density in addition to lengthening the cycling lifespan and guide the future development of HoMSs to further improve the performance of rechargeable batteries.