IDHA anions with strong chelating capabilities participate in the solvation shell of Zn 2+ and Na + . This interaction between IDHA anions and Na + serves to stabilize the solvated sheath, thereby enhancing the electrostatic shielding effect of Na + .

Rampant side reactions such as hydrogen evolution reaction (HER), corrosion and uncontrollable dendrite growth at anodes greatly impede the application of AZIBs. Herein, caprolactam (CPL) is employed as a crucial electrolyte medium to achieve the aim of highly reversible zinc anodes. CPL molecules exhibit a lower adsorption energy (-1.94 eV) than H2O and preferential binding with Zn anodes, resulting in a H2O-poor anode/electrolyte interface and an enhanced steric effect at the anode surface. This effect effectively hinders the contact between zinc metal and water molecules, consequently facilitating the uniform and controlled deposition of Zn2+. Furthermore, the combination between CPL and Zn2+ contributes to the optimization of solvation structures. Consequently, Zn/Zn batteries with CPL additives realized more than 2100 h stable cycling life under 1 mA cm-2 and 1 mAh cm-2. Moreover, Zn/Cu batteries with CPL additives achieved a reversible plating/stripping process for over 3000 cycles with high average CE of 99.4%. Besides, the assembled Zn/NH4V4O10 full batteries using electrolyte of ZnSO4/CPL also exhibited excellent cyclic performance. The batteries yielded 77.1 mAh g- 1 under the current density of 5 A g-1 after 1000 cycles. CPL demonstrates significant potential as a cost-effective and multifunctional electrolyte additive for achieving stable and reliable AZIBs.

High safety and stability in batteries are crucial factors for the large-scale application of lithium-ion technology. In this work, flame-retardant aluminum diethylphosphonite (ADP) is coated by urea-formaldehyde (UF) shell to conquer the side reactions caused by ADP during cycling process. And then the core@shell structured ADP@UF is combined with poly(ethylene oxide) (PEO), high thermal stability can be realized. When exposed to high temperatures, ADP@UF generates N & sdot; and P & sdot; radicals to eliminate the combustion the H & sdot; and OH & sdot; radical, to inhibit fire. By controlling the percentage of flame retardant added, PEO-ADP@UF has totally achieved the effect of inflaming retarding, realizing stable electrochemical properties at the same time. The -NH2 in UF forms hydrogen bonds with PEO, and acts as a Lewis base to promote the dissociation of lithium salts to increase the lithium-ion mobility number. Compared to PEO, battery with PEO-ADP@UF has outstanding cycling performance (103 mAh g-1 at 1 C, 2.5-4.2 V) and long service life (800 cycles). Flame-retardant aluminum diethylphosphonite (ADP) is coated by urea-formaldehyde (UF) shell to conquer the side reactions caused by ADP during cycling process. And then the core@shell structured ADP@UF is combined with poly(ethylene oxide) (PEO), electrolyte with high thermal stability can be realized. image

Flame retardants could improve the safety properties of lithium batteries (LBs) with the sacrifice of electrochemical performance due to parasitic reactions. To concur with this, we designed thermal-response clothes for hexachlorophosphazene (HCP) additives by the microcapsule technique with urea-formaldehyde (UF) resin as the shell. HCP@UF combines with polyacrylonitrile (PAN) by hydrogen bonds successfully to form PAN-HCP@UF as the flame-retardant solid polymer electrolyte. The hydrogen bonds ensure excellent mechanical properties of the polymer electrolyte. The multiscale free radical-annihilating agent HCP effectively eliminates hydrogen free radicals of electrolytes under high temperature, showing excellent flame retardation. During the operation of the battery, functional groups on the UF resin act as active sites to promote the migration of lithium ions, while the internal HCP is protected from electrochemical reaction. With 25% HCP@UF addition, the limiting oxygen index of the PAN-HCP@UF increases to 28% and the Li+ transfer number up to 0.80. By UF protection, the initial capacity retention rate of the Li||LFP battery that assembles with PAN-HCP@UF is 88.8% after 500 cycles at 0.5 C. Thus, the microcapsule-encapsulated approach is deemed to provide an innovative strategy to prepare high-safety solid-state LB with a stable long cycle life.

This work proposes glutamine (Gln) as a multifunctional electrolyte additive for highly stable and reversible Zn anodes in aqueous zinc-ion batteries.

Zinc (Zn) metal-based aqueous batteries are attracting tremendous attention facing grid-energy storage. However, the practical application has been severely impeded due to the challenges of Zn anode including the dendrites growth, side reactions and passivation layer accumulation. Here, an accessible solvent (ethanol, ETH) with low dielectric constant is utilized as an electrolyte additive to modulate the coordination environment of Zn2+ and the surface of Zn anode. The new assembled solvated ions reduce the inherent electrostatic interactions within the overall electrolyte, resulting in the efficient migration of Zn2+. In addition, the preferential adsorption of ETH on the Zn surface leads to the formation of an improved electric double layer (EDL), which effectively restricts water molecule access and regulates unique transfer channels of Zn2+. As a result, dense deposit with orientation plating is achieved. Zn||MnO2 full cells disclose an impressive capacity retention of 84.47% even after undergoing 2000 cycles at a high current density of 1 A g-1. This work provides a new insight into the effect of low dielectric constant additives on Zn2+ deposit for advanced aqueous zinc-ion batteries (AZIBs) development.

Due to the intrinsic safety and cost effectiveness, aqueous Zn-ion batteries (AZIBs) are considered a promising candidate for future energy storage systems. However, the widespread implementation of AZIBs faces significant obstacles due to various undesirable side reactions, including hydrogen evolution reaction (HER), corrosion, and uncontrolled dendrite growth at the anodes. Here, 4-hydroxybenzoic acid sodium salt (PHB) is employed in the ZnSO4 electrolyte to enable highly-reversible zinc anodes. PHB has a greater tendency to bind with the Zn surface, resulting in increased steric effects within the electrolyte. As a result, it hinders the direct interaction between anode and water while facilitating the uniform plating of Zn2+ . Zn/Zn batteries with PHB additives realized more than 1600 h stable cycling life under 1 mA cm-2 and 1 mAh cm-2 . Moreover, Zn/Cu batteries with PHB additives achieved a reversible plating/stripping process for over 500 cycles with high average CE of 98.6 %. In addition, the assembled Zn/NH4 V4 O10 batteries with PHB additive yielded 80.5 mAh g-1 after 1000 cycles at 10 A g-1 . The inexpensive and effective application of PHB as an electrolyte additive has the potential to significantly enhance the stability and dependability of ZIBs.

Quasi solid zinc batteries (QSZBs) based on gel electrolyte have performed as a significant application prospect as advanced high energy density electrochemical storage devices with safety, low cost, eco-friendliness, and flexibility. While, the practical application of QSZBs was enormously restricted by low ionic conductivity and poor strength of pure gel electrolyte. Here, in order to activate the zinc ion conduction in gel electrolyte, the kinds of inorganic fillers constituting the composite electrolyte was investigated. The theoretical study was also revealed by density functional theory to have deep insight into the mechanism. In particular, appropriate filler amount (ZnO#20) can make a noteworthy ion conductivity elevation (1.3 × 10-3 S cm-1) which is much better than the control sample (2.0 × 10-4 S cm-1) at -20 °C. As a result, the symmetric cell with ZnO#20 can achieve a long-term cycling life of over 1500 h. Moreover, the pouch cell coupled with vanadium pentoxide is assembled, and corresponding versatility is also identified with twisting, refrigeration (-20 °C) and cutting.

Aqueous Zn-ion batteries(AZIBs)are the potential options for the next-generation energy storage scenar-ios due to the cost effectiveness and intrinsic safety.Nevertheless,the industrial application of AZIBs is still impeded by a series of parasitic reactions and dendrites at zinc anodes.In this study,taurine(TAU)is used in electrolyte to simultaneously optimize the coordination condition of the ZnSO4 elec-trolyte and interfacial chemistry at the anode.TAU can preferentially adsorb with the zinc metal and induce an in situ stable and protective interface on the anode,which would avoid the connection between H2O and the zinc metal and promote the even deposition of Zn2+.The resulting Zn//Zn batteries achieve more than 3000 hours long cyclic lifespan under 1 mA cm-2 and an impressive cumulative capac-ity at 5 mA cm-2.Moreover,Zn//Cu batteries can realize a reversible plating/stripping process over 2,400 cycles,with a desirable coulombic efficiency of 99.75％(1 mA cm-2).Additionally,the additive endows Zn//NH4V4O10 batteries with more stable cyclic performance and ultrafast rate capability.These capabil-ities can promote the industrial application of AZIBs.

This work proposes layered NiCo–MnO2 as the cathode for ZIBs. The ordered nanostructure and atomic engineering endow NiCo–MnO2 with uniform stress distributions and excellent electrochemical performance.

Advanced interfacial engineering performs a forceful modulation effect on Zn2+ plating/stripping with simultaneous inhibition of hydrogen evolution reaction, chemical corrosion, and dendrite growth, which is responsible for high reversibility of Zn anode. Herein, a "two in one" interface engineering is developed to improve the reversibility of Zn anode, in which multi-functional Zn-5(NO3)(2)(OH)(8.)2H(2)O layer and preferential Zn (002) texture are constructed simultaneously. Due to nucleophilicity to Zn2+ arising from electronegativity, the layer can accelerate the desolvation process of [Zn (H2O)(6)](2+) and transfer kinetics of Zn2+ ions, leading to uniform nucleation and effective inhibition of water-induced side reactions. Meanwhile, the latter is beneficial to guiding Zn (002)-preferred orientation deposition with compact structure. Consequently, the Zn electrodes with such complementary interface modulation exhibit prominent reversibility. With an area capacity of 1 mAh cm(-2 )at 1 mA cm(-2), the symmetric cell operates steadily for 4000 h. Highly reversible Zn anode is maintained even at 50 mA cm(-2). For full cells coupled with MnO2 cathode, impressive rate capability and cycling stability with a high capacity beyond 100 mAh g(-1) at 1 A g(-1) after 2000 cycles are achieved. The results provide new insights into Zn anodes with high reversibility for next-generation aqueous zinc ion batteries.

Aqueous zinc ion batteries (AZIBs) are appealing increasing attention for large-scale energy storage systems (ESS) due to their intrinsic safety, low cost, and scalability. Unfortunately, the Zn metal anode suffers from chaotic side reactions, rampant dendrite growth and continuous hydrogen evolution, severely hampering the application of AZIBs. Herein, the trifunctional tranexamic acid (TXA) is introduced into aqueous electrolyte to form unique anode/electrolyte interface, enhance steric effect and regulate Zn2+ solvation structure. Theoretical calculations first illustrate the mechanism of TXA additive on Zn metal anode and electrolyte. Experimental results and molecular dynamic simulations further demonstrate the vital role of TXA in simultaneously regulating the anode interface chemistry and electrolyte environment. Consequently, Zn//Zn symmetric cells deliver a durable lifespan of over 2000 h at 1 mA cm–2, and a high cumulative capacity at 5 mA cm–2. A highly reversible Zn plating/stripping processes for over 1000 cycles in Zn//Cu asymmetric cells are also achieved. Moreover, the assembled Zn//NiCo-MnO2 and Zn//NH4V4O10 full cells exhibit stable cycling performance and high capacity retentions. This work proposes a novel and facile integrated electrolyte regulation strategy to realize dendrite-free Zn anodes and stable full cells, which is favorable for advanced AZIBs and beyond.

Ion migration and electron transmission are vital for manganese dioxides in zinc ion batteries. δ-MnO2 is believed to be more suitable for zinc ion storage due to its layered structure. However, the performance of δ-MnO2 is still hampered by the frustrating conductivity and sluggish reaction kinetics. Herein, atomic engineering is adopted to modify δ-MnO2 at the atomic level to obtain oxygen-deficient δ-MnO2 (N-MnO2). Meanwhile, hollow carbon microtubes (HCMTs) obtained from green and renewable energy grass are proposed as cross-connected electron transmission matrices (CETMs) for MnO2. The biomass-derived CETMs not only optimize reaction kinetics but also facilitate the ion storage performance of MnO2. The as-prepared N-MnO2@HCMTs exhibit high rate capability and enhanced pseudocapacitve behavior contributed by the oxygen-deficient N-MnO2 and CETMs. Ex situ analysis reveals the reversible insertion/extraction of H+ and Zn2+ in N-MnO2@HCMTs during charge/discharge processes. Moreover, the quasi-solid-state N-MnO2@HCMTs//Zn cells are assembled and they deliver extraordinary discharge capacity and a long cyclic lifespan. This study may provide insights for further exploration of cathode materials in AZIBs and promote the large-scale production of aqueous Zn-MnO2 batteries.

The in-situ formation mechanism of MgAl2O4 was introduced,focusing on the formation process by solid phase reaction and gas phase reaction as well as the phenomenon of secondary spinelization.The influencing factors of the in-situ MgAl2O4 formation and its effect on the microstructure and the properties of materials were systematically summarized for the Al2O3-MgO-MgAl2O4 system and the carbon-containing refractories systems.It was pointed out that the in-situ formation of MgAl2O4,including secondary spinelization,can regulate the microstructure and the service performance of materials.Its expansion effect can not only offset the shrinkage caused by sintering to improve the corrosion resistance of refractories,but also seriously restrict the reliability of functional refractories.The composition,the particle size,the atmosphere,and the temperature are important factors affecting the in-situ formation of MgAl2O4.In the carbon-containing materials systems,the solid-solid reaction and the gas-solid reaction coexist to produce MgAl2O4,which provides an effective way to further regulate the microstructure and the properties of materials through the reaction process.