This review highlights the recent encouraging research accomplishments achieved in the field of film-forming electrolyte additives for the protection of classified anode and cathode materials.

Magnesium (Mg)-based materials are promising candidates for hydrogen storage due to the low cost, high hydrogen storage capacity and abundant resources of magnesium for the realization of a hydrogen society. However, the sluggish kinetics and strong stability of the metal-hydrogen bonding of Mg-based materials hinder their application, especially for onboard storage. Many researchers are devoted to overcoming these challenges by numerous methods. Here, this review summarizes some advances in the development of Mg-based hydrogen storage materials related to downsizing and catalysis. In particular, the focus is on how downsizing and catalysts affect the hydrogen storage capacity, kinetics and thermodynamics of Mg-based hydrogen storage materials. Finally, the future development and applications of Mg-based hydrogen storage materials is discussed.

Transition metal oxides have been extensively studied as anodes in lithium ion batteries due to their high specific capacity. However, they face some challenges to realize their practical applications owing to their inherent drawbacks of poor electronic conductivity and large volume expansion during charge/discharge. In this work, a facile synthesis of ultrafine ZnO nanocrystals encapsulated in a 3D N-doped carbon nanosheet framework (ZnO–NCNF) is reported to tackle these issues and improve the performance. The ZnO–NCNF-700 composite maintains a reversible capacity of 770 mA h g⁻¹ at 500 mA g⁻¹ after 1000 cycles. At 1000 mA g⁻¹, a capacity of 572 mA h g⁻¹ is retained after 750 cycles. Even at higher current density of 10 000 mA g⁻¹, it still possesses a capacity of 148 mA h g⁻¹. Moreover, it maintains the structural integrity and its ion-diffusion coefficient increases by over three orders of magnitude. Also, the LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811)/ZnO–NCNF-700 full cell maintains a capacity of 531 mA h g⁻¹ after 60 cycles. The superior electrochemical performance might be ascribed to the reduced charge-transfer resistance, boosted Li⁺ diffusivity, mitigated breakage and structural integrity that originated from the decreased particle size and NCNF architecture. This work provides more insight into the lithium storage of ultrafine ZnO nanocrystals as anode electrode materials, and opens a new and facile strategy for developing a promising ZnO anode material for practical applications in lithium ion batteries.

Since limited energy density and intrinsic safety issues of commercial lithium-ion batteries (LIBs), solid-state batteries (SSBs) are promising candidates for next-generation energy storage systems. However, their practical applications are restricted by interfacial issues and kinetic problems, which result in energy density decay and safety failure. This review discusses the formation mechanisms of these issues from the perspective of typical solid-state electrolytes (SSEs) and provides an overview of recent advanced anode engineering for SSBs based on representative anodes including Li metal, graphite-based, and Si-based anodes, summarizing the advantages and problems of each strategy. The development of the anode-free batteries concept is demonstrated as well. Finally, recommendations are proposed for the potential directions in future research in anode engineering for SSBs.