Aqueous zinc-ion batteries are promising candidates as stationary storage systems for power-grid applications due to their high safety and low cost. The practical implementation of Zn-ion batteries currently still faces formidable challenges because of Zn dendrite growth, hydrogen evolution, and inadequate environmental adaptability. Herein, to address these challenges, a strategy of regulation of water molecules coordination in electrolyte is proposed via developing a cross-linked hydrophilic hydrogel polymer electrolyte. Within this system, the continuous hydrogen bond among H₂O molecules is disrupted and the isolated H₂O molecules are strongly bound with a polymeric matrix comprised of polyacrylamide, carboxymethyl cellulose, and ethylene glycol, which can restrain the activity of H₂O molecules, thus effectively alleviating Zn dendrite growth and hydrogen evolution and enhancing the anti-freezing ability. With this electrolyte, the Zn||Cu cell presents a high coulombic efficiency of 99.4% over 900 cycles and Zn||Zn symmetric cell exhibits high cycling stability, maintaining plating/stripping for over 1,700 h. Moreover, the assembled Zn||PANI device also demonstrates outstanding electrochemical performance over a wide-temperature range, including a long cycling life over 14,120 cycles at room temperature and an ultralong cycling surpassing 30,000 cycles even at − 40 °C. This showcases the manipulation of water coordination chemistry for advanced, highly adaptable batteries.

Anodes equipped with limited lithium offer a way to deal with the increasing market requirement for high-energy-density rechargeable batteries and inadequate global lithium reserves. Anode-free lithium-ion batteries (AFLBs) with zero excess metal could provide high gravimetric energy density and high volumetric energy density. Moreover, the elimination of lithium with a bare current collector on the anode side can reduce metal consumption, simplify the cell technological procedure, and improve manufacturing safety. However, some great challenges, such as insufficient cycling stability, significant lithium dendrite growth, as well as unstable solid electrolyte interface, impede the commercial application of AFLBs. Fortunately, significant progress has been made for AFLBs with enhanced electrode stability and improved cycling performance. This review highlights research on the design of anode-free lithium-ion batteries over the past two decades, presents an overview of the main advantages and limitations of these designs, and provides improvement strategies including the modification of the current collectors, improvement of the liquid electrolytes, and optimization of the cycling protocols. Prospects are also given to broaden the understanding of the electrochemical process, and it is expected that the further development of these designs can be accelerated in both scientific research and practical applications.

Vacancy engineering is widely considered an effective approach to modulate the internal electronic structure of electrode materials, enhancing charge‐transfer processes/reactions and leading to excellent energy storage properties. Nevertheless, several current techniques of vacancy engineering, such as controlled solvent thermal growth, plasma bombardment, and chemical etching, suffer from high energy inputs and uncontrollable processing kinetics. Herein, a facile and energy‐efficient technique of metal ion‐assisted shear exfoliation is proposed to synthesize 2D MoS ₂ with edge S‐vacancies as an anode for sodium ion batteries. Thanks to the implementation of this vacancy technique, few‐layer MoS ₂ anode with sulfur defects at the edge presents remarkable rate performance (399.91 mAh g ⁻¹ at a current density of 5 A g ⁻¹ ) and demonstrates high average capacity with exceptional stability (460.71 mAh g ⁻¹ at 1 A g ⁻¹ after 100 cycles) when utilized in sodium‐ion batteries. The superior electrochemical performance of this elaborate anode can be ascribed to the enhanced electrochemical kinetics and reaction reversibility resulting from the presence of a vacancy defect architecture. This study is expected to provide an effective avenue to develop vacancy defect electrodes for advanced batteries.

Potassium (K) metal anodes have attracted widespread attention in the realm of energy storage due to their cost-effectiveness, abundance, and high theoretical capacity. However, the undesirable K-dendrite growth accompanied by void formation upon prolonged cycling presents formidable obstacles to their real-world applications. Herein, phosphorus-based electrolytes are developed based on the electrolyte additive design criteria of steric hindrance, polar ability, and decomposition preference to enhance the anode/electrolyte interface stability. The additive triphenyl phosphate in the electrolyte could regulate the K⁺ solvation structure and promote the formation of an inorganic P-rich solid-electrolyte interphase layer, thus ultimately mitigating interfacial polarization, augmenting transport properties, and stabilizing the interphase. Therefore, we have successfully achieved a dense and dendrite-free K metal anode, exhibiting improved coulombic efficiency and prolonged lifespan. Our design tactic demonstrates the promising application of K metal batteries in achieving elevated safety, high energy densities, and extended operational longevity.

The high-temperature stability of the electrode–electrolyte interface in layered oxides is enhanced by electrolyte design criteria.

In metallurgy, the quenching process often induces changes in certain material properties, such as hardness and ductility, through the rapid cooling of a workpiece in water, gas, oil, polymer, air, or other fluids. Given that lithium-ion batteries operate under relatively benign conditions, conventional rapid cooling does not significantly affect the property variations in their internal electrode materials during normal use. However, thermal runaway presents an exception due to its dramatic temperature fluctuations from room temperature to several hundred degrees Celsius. In this study, we investigated NCM811 cathodes in 18,650 batteries subjected to transient thermal runaway followed by rapid cooling using several advanced analytical techniques. The results reveal a phenomenon characterized by intergranular cracking within NCM811 cathode materials when exposed to rapid cooling during transient thermal runaway. Furthermore, lithium-ion cells utilizing reused NCM-182.4 electrodes in fresh electrolyte demonstrate a reversible capacity of 231.4 mAh/g after 30 cycles at 0.1 C, highlighting the potential for reusing NCM811 cathodes in the lithium-ion battery recycling process. These findings not only illustrate that NCM811 particles may experience intergranular cracking when subjected to rapid cooling during transient thermal runaway, but also the rapidly cooled NCM811 electrodes exhibit potential for reuse.