With the exponential growth of portable electronic devices and wearable technologies, batteries are now required to deliver not only high energy density and extended cycling performance but also enhanced safety and exceptional durability. Inspired by self-repair mechanisms observed in natural systems, the self-healing strategy offers a promising solution for enabling batteries to resist external physical and chemical damage. In this review, we provide a detailed exploration of the application of self-healing materials in battery components, including electrodes, electrolytes, and encapsulation layers. We analyze the advantages and limitations of various self-healing mechanisms, highlighting their roles in optimizing battery performance. By presenting a comprehensive synthesis of existing research, we identify potential pathways for advancing the development of self-healing batteries, as well as the key challenges and opportunities within this field. Our aim is to promote the practical integration of self-healing batteries in smart and flexible electronic devices, paving the way for safer, more reliable, and longer-lasting energy storage systems.

All-solid-state lithium metal batteries (ASSLMBs) with solid electrolytes (SEs) have emerged as a promising alternative to liquid electrolyte-based Li-ion batteries due to their higher energy density and safety. However, since ASSLMBs lack the wetting properties of liquid electrolytes, they require stacking pressure to prevent contact loss between electrodes and SEs. Though previous studies showed that stacking pressure could impact certain performance aspects, a comprehensive investigation into the effects of stacking pressure has not been conducted. To address this gap, we utilized the Li₆PS₅Cl solid electrolyte as a reference and investigated the effects of stacking pressures on the performance of SEs and ASSLMBs. We also developed models to explain the underlying origin of these effects and predict battery performance, such as ionic conductivity and critical current density. Our results demonstrated that an appropriate stacking pressure is necessary to achieve optimal performance, and each step of applying pressure requires a specific pressure value. These findings can help explain discrepancies in the literature and provide guidance to establish standardized testing conditions and reporting benchmarks for ASSLMBs. Overall, this study contributes to the understanding of the impact of stacking pressure on the performance of ASSLMBs and highlights the importance of careful pressure optimization for optimal battery performance.

The layer-dependent properties are still unclarified in two-dimensional (2D) vertical heterostructures. In this study, we layer-by-layer deposited semimetal β-In₂Se₃ on monolayer MoS₂ to form vertical β-In₂Se₃/MoS₂ heterostructures by chemical vapor deposition. The defect-mediated nucleation mechanism induces β-In₂Se₃ nanosheets to grow on monolayer MoS₂, and the layer number of stacked β-In₂Se₃ can be precisely regulated from 1 layer (L) to 13 L by prolonging the growth time. The β-In₂Se₃/MoS₂ heterostructures reveal tunable type-Ⅱ band alignment arrangement by altering the layer number of β-In₂Se₃, which optimizes the internal electron transfer. Meanwhile, the edge atomic structure of β-In₂Se₃ stacking on monolayer MoS₂ shows the reconstruction derived from large lattice mismatch (~ 29%), and the presence of β-In₂Se₃ also further increases the electrical conductivity of β-In₂Se₃/MoS₂ heterostructures. Attributed to abundant layer-dependent edge active sites, edge reconstruction, improved hydrophilicity, and high electrical conductivity of β-In₂Se₃/MoS₂ heterostructures, the edge of β-In₂Se₃/MoS₂ heterostructures exhibits excellent electrocatalytic hydrogen evolution performance. Lower onset potential and smaller Tafel slope can be observed at the edge of monolayer MoS₂ coupled with 13-L β-In₂Se₃. Hence, the outstanding conductive layers coupled with edge reconstruction in 2D vertical heterostructures play decisive roles in the optimization of electron energy levels and improvement of layer-dependent catalytic performance.