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Although RuO2is a potential electrocatalyst for Li–O2batteries (LOBs), its high price limits its large-scale application. Recent reports suggest that combining small amounts of RuO2with nonprecious supports is a wise choice for developing low-cost bifunctional electrocatalysts. Here, a series of cobalt-containing supports, including Co3O4, Co-NCNTFs, and NiCo2O4, are designed to support RuO2to explore their electrocatalytic performance in LOBs. Among them, RuO2@NiCo2O4exhibits significantly better catalytic activity and stability compared to the RuO2@Co3O4and RuO2@Co-NCNTF counterparts. Notably, RuO2@NiCo2O4achieved a low overpotential of 0.51 V and exceptional long-term reversibility exceeding 2000 h at a capacity limit of 1000 mAh g–1with a current density of 500 mA g–1, suggesting that the electronic conductance, microstructure, and electrochemical stability of the support are crucial factors in designing RuO2-based electrocatalysts for LOBs. This research provides valuable insights into designing cost-effective and efficient catalysts for advancing energy storage technologies.

In the recycling process of spent lithium-ion batteries, the presence of a certain amount of aluminum ions not only increases the alkali consumption for iron and aluminum removal but also affects the purity of nickel, cobalt, manganese salts, and iron phosphate, thereby hindering the preparation of battery-grade products. Herein, the precipitation process of aluminum hydroxide from supersaturated sodium aluminate solution was investigated across varying temperatures with the addition of minimal quantity of active seeds. X-ray diffraction analysis identified gibbsite and bayerite crystallization in the active seed phases. Assessment of product particle size distribution using power spectral density indicated median particle sizes of 9.70, 18.89, 35.32, and 51.78 μm at temperatures of 45, 55, 65, and 75 °C, respectively, suggesting that elevated temperatures favored product particle size growth. Additionally, to elucidate the precipitation mechanism, the kinetic equation was augmented with the inclusion of instantaneous seed coefficient and specific surface area, yielding an apparent activation energy of 83.52 kJ/mol.

Lithium–sulfur (Li–S) batteries have high theoretical energy density and are regarded as a promising candidate for next-generation energy storage systems. However, their practical applications are hindered by the slow kinetics of sulfur conversion and polysulfide shuttling. In particular, large-scale pouch cells show much poor cyclability. Here, we develop a high-efficiency catalyst of V-doped CoSe2by studying the binary CoSe2–VSe2system and confirming its effectiveness in accelerating polysulfide conversion. The coin cell tests reveal an initial capacity of 1414 mAh g–1at 0.1 C and 1049 mAh g–1at 1 C and demonstrate 1000 times cyclability with a decaying rate of 0.05% per cycle. Furthermore, the assembly and construction of pouch cells were optimized with monolithic three-dimensional (3D) electrodes and a multistacking strategy. Specifically, a 3D metallic scaffold (3MS) was developed to host V-doped CoSe2nanowires and sulfur. In addition, Janus microspheres of C@TiO2were synthesized to capture polar polysulfides with their polar part of TiO2and adsorb nonpolar sulfur with their nonpolar part of carbon. By integrating with 3MS, C@TiO2microspheres can block all ion channels of 3MS and only allow Li ions in and out. These integral designs and monolithic structures enable multistacking pouch cells with high cyclability. A high-loading pouch cell was demonstrated with a total capacity of 700 mAh. The cell can be cycled for 70 times with a capacity retention of 65.7%. In brief, this work provides an integral strategy of catalyst design and overall 3D assembly for practical Li–S batteries in a large pouch cell format.

Metal–air batteries are a type of electrochemical cell that generates electrical energy by combining metal and oxygen from the air. They are a promising technology for energy storage and portable devices because of their high energy density, low cost, and environmental friendliness. However, the discharge products of these batteries are notoriously difficult to decompose, resulting in a high overpotential. Recent works have shown that semiconductors can capture solar energy and store it in batteries. When exposed to light, photocatalysts generate carriers (strong redox pairs), thereby increasing the electron migration rate and significantly reducing the overpotential of the metal–air battery reaction. Nevertheless, single photocatalysts often exhibit poor cycle performance due to serious carrier recombination. This review paper begins by briefly describing the fundamentals of photoelectrochemistry and then focuses on commonly used photocathode design principles and various reported photocatalysts. It also discusses the main challenges and issues caused by light, such as photocorrosion and electrolyte decomposition. Finally, the critical issues associated with photo electrodes, electrolytes, and electrode/electrolyte interfaces are emphasized, and perspectives on the development of high-performance light-assisted metal–air batteries are presented.