The development of efficient and affordable electrode materials is key to the construction of clean energy storage systems. Transition-metal chalcogenophosphates (TMPX₃, where TM represents Ni, Fe, Zn, V, Mn, Co, etc., and X denotes S, Se, or Te) are a promising class of two-dimensional (2D) layered materials with great potential for energy storage, photoelectrocatalysis, and electronic devices due to their unique electronic structure and tunable bandgap. In this review, we systematically summarise the latest research progress on TMPX₃ materials, adopting a pioneering multidimensional analysis framework to overcome the limitations of a unified single perspective. Firstly, we reveal the mechanisms of P–S bond anisotropy and TM coordination on the energy band structure from the atomic scale; secondly, through the comparative analysis of the existing preparation methods and regulation strategies, the optimised pathways for precise control of the number of layers and large-scale production are proposed. On this basis, we focus on the applications of TMPX₃ in photoelectrocatalysis and metal batteries, and elucidate the cross-scale correlation mechanism between its electronic/interfacial properties and macroscopic performance. Finally, the challenges and future opportunities of the material are presented, with the aim of providing valuable insights into the multi-field, precisely coupled design and energy storage applications of TMPX₃ materials.

The leakage of liquid electrolyte and the formation of lithium dendrites pose challenges to safety and stability of lithium metal batteries (LMBs). The appearance of gel polymer electrolyte (GPE) has obviously improved the safety of traditional LMBs. However, the limited inhibition of GPE on lithium dendrites is detrimental to the safety of LMBs. Herein, a kind of poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/gelatin (GN) GPE with high ionic conductivity, high-temperature resistance, and flame-retardancy, was prepared by electrospinning and soaking method. Utilizing the electrospinning network of PVDF-HFP, its affinity to liquid electrolytes, makes this GPE more beneficial to ions transport and the formation of gel. And, the GN with sol–gel properties, enhances the mechanical property (13.5 MPa) of HFP-GN GPE. Meanwhile, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) suggest that the attraction of polar groups of GN to Li⁺ can regulate the distribution of Li⁺ and protect Li anodes. Consequently, the application of HFP-GN GPEs to LMBs with cathodes of LiFePO₄ and LiCoO₂ deliver excellent electrochemical performances: after 300 cycles, the LiFePO₄/HFP-GN GPE/Li battery keeps a low capacity decay rate of 0.09% at 5 C; after 400 cycles at 2 C, the LiCoO₂/HFP-GN GPE/Li cell retains a high capacity retention of 74%. This GPE is demonstrated for the application prospect of safe LMBs.

Heterogeneous catalysts promoting efficient production of reactive species and dynamically stabilized electron transfer mechanisms for peroxomonosulfates (PMS) still lack systematic investigation. Herein, a more stable magnetic layered double oxides (CFLDO/N-C), was designed using self-polymerization and high temperature carbonization of dopamine. The CFLDO/N-C/PMS system effectively activated PMS to remove 99% (k = 0.737 min⁻¹) of tetracycline (TC) within 10 min. The CFLDO/N-C/PMS system exhibited favorable resistance to inorganic anions and natural organics, as well as satisfactory suitability for multiple pollutants. The magnetic properties of the catalyst facilitated the separation of catalysts from the liquid phase, resulting in excellent reproducibility and effectively reducing the leaching of metal ions. An electronic bridge was constructed between cobalt (the active platform of the catalyst) and PMS, inducing PMS to break the O–O bond to generate the active species. The combination of static analysis and dynamic evolution confirmed the effective adsorption of PMS on the catalyst surface as well as the strong radical-assisted electron transfer process. Eventually, we further identified the sites where the reactive species attacked the TC and evaluated the toxicity of the intermediates. These findings offer innovative insights into the rapid degradation of pollutants achieved by transition metals in SR-AOPs and its mechanistic elaboration.

Sodium-carbon dioxide (Na-CO₂) batteries are regarded as promising energy storage technologies because of their impressive theoretical energy density and CO₂ reutilization, but their practical applications are restricted by uncontrollable sodium dendrite growth and poor electrochemical kinetics of CO₂ cathode. Constructing suitable multifunctional electrodes for dendrite-free anodes and kinetics-enhanced CO₂ cathodes is considered one of the most important ways to advance the practical application of Na-CO₂ batteries. Herein, RuO₂ nanoparticles encapsulated in carbon paper (RuCP) are rationally designed and employed as both Na anode host and CO₂ cathode in Na-CO₂ batteries. The outstanding sodiophilicity and high catalytic activity of RuCP electrodes can simultaneously contribute to homogenous Na⁺ distribution and dendrite-free sodium structure at the anode, as well as strengthen discharge and charge kinetics at the cathode. The morphological evolution confirmed the uniform deposition of Na on RuCP anode with dense and flat interfaces, delivering enhanced Coulombic efficiency of 99.5% and cycling stability near 1500 cycles. Meanwhile, Na-CO₂ batteries with RuCP cathode demonstrated excellent cycling stability (>350 cycles). Significantly, implementation of a dendrite-free RuCP@Na anode and catalytic-site-rich RuCP cathode allowed for the construction of a symmetric Na-CO₂ battery with long-duration cyclability, offering inspiration for extensive practical uses of Na-CO₂ batteries.

Low electrolyte/sulfur ratio (E/S) is an important factor in increasing the energy density of lithium-sulfur batteries (LSBs). Recently, the E/S has been widely lowered using catalytic hosts that can suppress “shuttle effect” during cycling by relying on a limited adsorption area. However, the shelf-lives of these cathodes have not yet received attention. Herein, we show that the self-discharge of sulfur cathodes based on frequently-used catalytic hosts is serious under low E/S because the “shuttle effect” during storage process caused by polysulfides (PSs) disproportionation cannot be suppressed using a limited adsorption area. We further prove that the adsorption strength toward PSs, which is unfortunately weak in commonly-used catalytic hosts, is critical for effectively hindering the disproportionation of the PSs. Subsequently, to verify this conclusion, we prepare a sulfur-doped titanium nitride (S-TiN) catalytic array host. As the adsorption strength and catalytic activity of TiN can be improved by S doping simultaneously, the constructed S/S-TiN cathodes under a low E/S (6.5 μL·mg⁻¹) exhibit better shelf-life and cycle-stability than those of S/TiN cathodes. Our work suggests that enhancing the adsorption strength of catalytic hosts, while maintaining their function to reduce E/S, is crucial for practical LSBs.

While sulfide solid electrolytes such as Na₁₁Sn₂PS₁₂ can allow fast transport of Na⁺ ions, their utilization in solid sodium ion batteries is rather unsuccessful since they are not electrochemically compatible to both high-voltage cathodes and sodium metal anode. In this work, we devise an effective approach toward realizing solid sodium ion batteries, using the Na₁₁Sn₂PS₁₂ electrolyte and slurry-coated NASICON-type Na₃MnTi(PO₄)₃@C as high-voltage cathode, highly beneficial for low processing cost and high content/loading of active cathode matter. We report that through significantly improved integrity of electrolyte-cathode interface, such solid sodium ion batteries can deliver outstanding cycling and rate performance, with a charge voltage resilience up to 4.1 V, a high cathode discharge capacity of 128.7 mAh g⁻¹ against the Na₃MnTi(PO₄)₃@C in cathode is achieved at 0.05 C, and capacity retention ratio of 82% with a rate of 0.1 C is realized after prolonged cycling at room temperature. Besides, we demonstrate that such a solid sodium ion battery can even perform at a sub-zero Celsius temperature of −10°C, when the conventional control cell using liquid electrolyte completely fail to function. This work is to offer a dependable avenue in engineering next generation of safe solid ion batteries based on highly sustainable and much cheaper material resources.

Domain boundaries are regarded as the effective active sites for electrochemical energy storage materials due to defects enrichment therein. However, layered double hydroxides (LDHs) tend to grow into single crystalline nano sheets due to their unique two-dimentional (2D) lattice structure. Previously, much efforts were made on the designing hierarchical structure to provide more exposed electroactive sites as well as accelerate the mass transfer. Herein, we demonstrate a strategy to introduce low angle grain boundary (LAGB) in the flakes of Ni/Co layered double hydroxides (NiCo-LDHs). These defect-rich nano flakes were self-assembled into hydrangea-like spheres that further constructed hollow cage structure. Both the formation of hierarchical structure and grain boundaries are interpreted with the synergistic effect of Ni²⁺/Co²⁺ ratio in an “etching-growth” process. The domain boundary defect also results in the preferential formation of oxygen vacancy (Vo). Additionally, density functional theory (DFT) calculation reveals that Co substitution is a critical factor for the formation of adjacent lattice defects, which contributes to the formation of domains boundary. The fabricated battery-type Faradaic NiCo-LDH-2 electrode material exhibits significantly enhanced specific capacitance of 899 C·g⁻¹ at a current density of 1 A·g⁻¹. NiCo-LDH-2//AC asymmetric capacitor shows a maximum energy density of 101.1 Wh·kg⁻¹ at the power density of 1.5 kW·kg⁻¹.