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Co–N–C is a promising oxygen electrochemical catalyst due to its high stability and good durability. However, due to the limited adsorption ability improvement for oxygen-containing intermediates, it usually exhibits inadequate catalytic activity with 2-electron pathway and high selectivity of hydrogen peroxide. Herein, the adsorption of Co–N–C to these intermediates is modulated by constructing heterostructures using transition metals and their derivatives based on d-band theory. The heterostructured nanobelts with MoC core and pomegranate-like carbon shell consisting of Co nanoparticles and N dopant (MoC/Co–N–C) are engineered to successfully modulate the d band center of active Co–N–C sites, resulting in a remarkably enhanced electrocatalysis performance. The optimally performing MoC/Co–N–C exhibits outstanding bi-catalytic activity and stability for the oxygen electrochemistry, featuring a high wave-half potential of 0.865 V for the oxygen reduction reaction (ORR) and low overpotential of 370 mV for the oxygen evolution reaction (OER) at 10 mA cm−2. The zinc air batteries with the MoC/Co–N–C catalyst demonstrate a large power density of 180 mW cm−2 and a long cycling lifespan (2000 cycles). The density functional theory calculations with Hubbard correction (DFT + U) reveal the electron transferring from Co to Mo atoms that effectively modulate the d band center of the active Co sites and achieve optimum adsorption ability with “single site double adsorption” mode.

The anion end of zwitterions can interact with water around the electrode/electrolyte interface and promote the zinc plating/stripping kinetics, while their cation end can be adsorbed on the metallic zinc surface and homogenize zinc plating/stripping.

The N doped porous carbon and ZrO2 composite (NC@ZrO2) with a synergistic pseudocapacitive effect provides abundant active sites for zinc ions and favors fast ion diffusion, ensuring remarkable rate performance and long cycling stability.

Lattice distortion and structure collapse are two intrinsic issues of intercalative-type electrodes derived from repeated ion shuttling. In contrast, rechargeable iodine batteries (RIBs) based on the conversion reaction of iodine stand out for high reversibility and satisfying voltage output characteristics no matter when dealing with both monovalent and multivalent ions. Foreseeable performance superiorities lead to an influx of considerable focus and thus a renaissance in RIBs. This review provides a comprehensive overview of the fundamental chemistry of RIBs from the perspectives of physicochemical properties, conversion mechanism, and existing issues. Furthermore, we refine the optimization strategies for high-performance RIBs, focusing on physical adsorption and chemical interaction strengthening, electrolytes regulation, and nanoscale-iodine design. Then the pros and cons of tremendous RIBs are compared and specified. Ultimately, we conclude with remaining challenges and perspectives to our best knowledge, which may inspire the construction of next-generation RIBs.

One of the major obstacles hindering the application of zinc metal batteries is the contradictory demands from the Zn metal anode and cathodes. At the anode side, water induces serious corrosion and dendrite growth, remarkably suppressing the reversibility of Zn plating/stripping. At the cathode side, water is essential because many cathode materials require both H+ and Zn2+ insertion/extraction to achieve a high capacity and long lifespan. Herein, an asymmetric design of inorganic solid-state electrolyte combined with hydrogel electrolyte is presented to simultaneously meet the as-mentioned contrary requirements. The inorganic solid-state electrolyte is toward the Zn anode to realize a dendrite-free and corrosion-free highly reversible Zn plating/stripping, and the hydrogel electrolyte enables consequent H+ and Zn2+ insertion/extraction at the cathode side for high performance. Therefore, there is no hydrogen and dendrite growth detected in cells with a super high-areal-capacity up to 10 mAh·cm−2 (Zn//Zn), ~5.5 mAh·cm−2 (Zn//MnO2) and ~7.2 mAh·cm−2 (Zn//V2O5). These Zn//MnO2 and Zn//V2O5 batteries show remarkable cycling stability over 1000 cycles with 92.4% and over 400 cycles with 90.5% initial capacity retained, respectively.

The chlorine-based redox reaction (ClRR) could be exploited to produce secondary high-energy aqueous batteries. However, efficient and reversible ClRR is challenging, and it is affected by parasitic reactions such as Cl2 gas evolution and electrolyte decomposition. Here, to circumvent these issues, we use iodine as positive electrode active material in a battery system comprising a Zn metal negative electrode and a concentrated (e.g., 30 molal) ZnCl2 aqueous electrolyte solution. During cell discharge, the iodine at the positive electrode interacts with the chloride ions from the electrolyte to enable interhalogen coordinating chemistry and forming ICl3-. In this way, the redox-active halogen atoms allow a reversible three-electrons transfer reaction which, at the lab-scale cell level, translates into an initial specific discharge capacity of 612.5 mAh gI2−1 at 0.5 A gI2−1 and 25 °C (corresponding to a calculated specific energy of 905 Wh kgI2−1). We also report the assembly and testing of a Zn | |Cl-I pouch cell prototype demonstrating a discharge capacity retention of about 74% after 300 cycles at 200 mA and 25 °C (final discharge capacity of about 92 mAh).

Aqueous zinc metal batteries are appealing candidates for grid energy storage. However, the inadequate electrochemical reversibility of the zinc metal negative electrode inhibits the battery performance at the large-scale cell level. Here, we develop practical ampere-hour-scale aqueous Zn metal battery pouch cells by engineering the electrolyte solution. After identifying the proton reduction as the primary source of H2 evolution during Zn metal electrodeposition, we design an electrolyte solution containing reverse micelle structures where sulfolane molecules constrain water in nanodomains to hinder proton reduction. Furthermore, we develop and validate an electrochemical testing protocol to comprehensively evaluate the cell’s coulombic efficiency and zinc metal electrode cycle life. Finally, using the reverse micelle electrolyte, we assemble and test a practical ampere-hour Zn||Zn0.25V2O5•nH2O multi-layer pouch cell capable of delivering an initial energy density of 70 Wh L−1 (based on the volume of the cell components), capacity retention of about 80% after 390 cycles at 56 mA g−1cathode and ~25 °C and prolonged cycling for 5 months at 56 mA g−1cathode and ~25 °C.

The development of intercalation anodes with high capacity is key to promote the progress of "rocking-chair" Zn-ion batteries (ZIBs). Here, layered BiOI is considered as a promising electrode in ZIBs due to its large interlayer distance (0.976 nm) and low Zn

Self-charging power systems collecting energy harvesting technology and batteries are attracting extensive attention. To solve the disadvantages of the traditional integrated system, such as highly dependent on energy supply and complex structure, an air-rechargeable Zn battery based on MoS2/PANI cathode is reported. Benefited from the excellent conductivity desolvation shield of PANI, the MoS2/PANI cathode exhibits ultra-high capacity (304.98 mAh g−1 in N2 and 351.25 mAh g−1 in air). In particular, this battery has the ability to collect, convert and store energy simultaneously by an air-rechargeable process of the spontaneous redox reaction between the discharged cathode and O2 from air. The air-rechargeable Zn batteries display a high open-circuit voltage (1.15 V), an unforgettable discharge capacity (316.09 mAh g−1 and the air-rechargeable depth is 89.99%) and good air-recharging stability (291.22 mAh g−1 after 50 air recharging/galvanostatic current discharge cycle). Most importantly, both our quasi-solid zinc ion batteries and batteries modules have excellent performance and practicability. This work will provide a promising research direction for the material design and device assembly of the next-generation self-powered system.

Abstract Transition metal–nitrogen–carbon materials (M–N–Cs), particularly Fe–N–Cs, have been found to be electroactive for accelerating oxygen reduction reaction (ORR) kinetics. Although substantial efforts have been devoted to design Fe–N–Cs with increased active species content, surface area, and electronic conductivity, their performance is still far from satisfactory. Hitherto, there is limited research about regulation on the electronic spin states of Fe centers for Fe–N–Cs electrocatalysts to improve their catalytic performance. Here, we introduce Ti3C2 MXene with sulfur terminals to regulate the electronic configuration of FeN4 species and dramatically enhance catalytic activity toward ORR. The MXene with sulfur terminals induce the spin-state transition of FeN4 species and Fe 3d electron delocalization with d band center upshift, enabling the Fe(II) ions to bind oxygen in the end-on adsorption mode favorable to initiate the reduction of oxygen and boosting oxygen-containing groups adsorption on FeN4 species and ORR kinetics. The resulting FeN4–Ti3C2Sx exhibits comparable catalytic performance to those of commercial Pt-C. The developed wearable ZABs using FeN4–Ti3C2Sx also exhibit fast kinetics and excellent stability. This study confirms that regulation of the electronic structure of active species via coupling with their support can be a major contributor to enhance their catalytic activity.

Magnesium ion batteries (MIBs), due to the low redox potential of Mg, high theoretical capacity, dendrite-free magnesiation, and safe nature, have been recognized as a post-lithium energy storage system. However, an ongoing challenge, sluggish Mg

A Zn-NO2− battery with C/Co3O4 catalyst cathode is developed as an energy-output electrocatalytic system that can simultaneously convert NO2− to NH3 with high faradaic efficiency and supply electricity with a power density of 6.03 mW cm−2.

Both organic and aqueous zinc–selenium batteries deliver a competitive capacity with a higher plateau voltage than traditional zinc ion batteries.

Spatial gradient fluorinated alloy (GFA) with ZnF2 in the outmost region and CuZn alloy in the inner region that jointly contribute to a highly reversible Zn-metal anode.

Rechargeable AAIBs were assembled with AlCl3/LiTFSI solutions as electrolytes. The addition of an appropriate concentration of LiTFSI can effectively impede the HER activity and Al corrosion, leading to a highly reversible Al anode.

An amino-functionalized metal–organic framework achieves efficient capture–diffusion–conversion of CO2.

Ultrahigh oxygen doping content in carbon quantum dots enables excellent H2O2 selectivity and great potential in on-site green H2O2 production.

A novel strategy of applying external magnetic fields is proposed to tackle the challenging alkaline Zn dendrite issue. Benefiting from the magnetohydrodynamic effect, the ultra-flat zinc deposit and long-term cycling stability of the Zn battery was achieved.

Although a large number of intercalation cathode materials for aqueous Zn batteries have been reported, limited intercalation capacity precludes achieving a higher energy density. Here we develop a high-performance aqueous Zn battery based on BiSb alloy (Bi0.5Sb0.5) using a high-concentrated strong-basic polyelectrolyte. We demonstrate that a conversion-dissolution/deposition electrochemical mechanism (BiSb ↔ Bi + SbO2− ↔ Bi + SbO3− ↔ Bi2O3) through in situ X-ray diffraction (XRD), Raman, and ex-situ X-ray photoelectron spectrometry (XPS) characterizations with the help of density functional theory calculations. The BiSb cathode delivers large capacity of 512 mAh g−1 at 0.3 Ag−1 and superior rate capability of 90 mAh g−1 even at 20 Ag−1, and long-term cyclability with capacity retentions of 184 mAh g−1 after 600 cycles at 0.5 Ag−1 and 130 mAh g−1 after 1300 cycles at 1 Ag−1. Remarkably, even at temperatures as low as −10 and −20 °C, capacities of 210 and 197 mAh g−1 are reserved at 1 Ag−1, respectively. Moreover, the prepared pouch Zn//BiSb battery delivers a high energy density of 303 Wh kg−1BiSb at 0.3 Ag−1. When coupled with a high concentration polyelectrolyte, the Zn/BiSb battery exhibits an excellent performance over a wide temperature range (−40 to 40 °C). Our research reveals the metal cathode is promising for Zn batteries to achieve a high performance with the unique mechanism and alloys can be an effective approach to stabilize metal electrodes for cycling.

Aqueous potassium-ion batteries are long-term pursued, due to their excellent performance and intrinsic superiority in safe, low-cost storage for portable and grid-scale applications. However, the notorious issues of K-ion battery chemistry are the inferior cycling stability and poor rate performance, due to the inevitably destabilization of the crystal structure caused by K-ions with pronouncedly large ionic radius. Here, we resolve such issues by reconstructing commercial vanadium oxide (α-V

Summary Wearable batteries suffer from the chaotic state where the wearable concept is indiscriminately used regardless of the significant differences in flexibility, energy density, and other aspects, because of the difference between wearable batteries and commercial wearable electronics. Here, we initially present the chaotic state of wearable batteries based on the battery chemistry. Then, the specific requirements of wearable electronics are refined in terms of multifunctional flexible electronics and close-fitting health monitoring electronics. Restrained by the trade-off between energy density and flexibility, we propose to subdivide wearable batteries into unidirectional (bendable) and omnidirectional (soft) deformable batteries, aiming at better positioning flexible batteries and practically powering wearable electronics. These two types of wearable batteries are conceptually defined, and the promising candidates are proposed based on the match with commercial wearable electronics. Finally, we summarize the advances and present the challenges in wearable batteries to promote the development of this prosperous field.

Alkaline aqueous batteries such as the Zn||Ni batteries have attracted substantial interests due to their merits of high energy density, high safety and low cost. However, the freeze of aqueous electrolyte and the poor cycling stability in alkaline condition have hindered their operation in subzero conditions. Herein, we construct a stable aqueous electrolyte with lowest freezing point down to -90 °C by adding dimethyl sulfoxide (DMSO) as alkaline tolerant antifreezing additive into 1 M KOH solution. Meanwhile, we find the DMSO can also retard Zn anode corrosion and prevent Zn dendrite formation in alkaline condition, which enables the Zn plating/stripping over 700 h cycle at 1 mA cm

Anionic redox reactions would achieve a high capacity than typical transition-metal-oxide cathodes, offering a low-cost chemistry to advance the energy storage capability of lithium-ion batteries. Li-Cl2 chemistry using anionic redox reactions of Cl0/−1 shows superior operation voltage (~ 3.8 V) and capacity (756 mAh g− 1). However, a redox-active and reversible chlorine cathode has not been developed in organic electrolytes-based lithium-ion batteries. Chlorine ions bonded by ionic bonding hardly dissolve in organic electrolyte, imposing a thermodynamic barrier for redox reactions. Meanwhile, chlorine gas is easily formed during oxidation. Herein, we report an interhalogen compound, iodine trichloride (ICl3), as the cathode to address these two issues. In-situ and ex-situ spectroscopy data and calculations reveal that reduced Cl− ions are partially dissolved in the electrolyte, and oxidized Cl0 is anchored by forming interhalogen bonds with I. A reversible Li-Cl2 at room temperature is developed, which delivers a specific capacity of 302 mAh g− 1 at 425 mA g− 1, and a 73.8% capacity retention at 1250 mA g− 1. The demonstration of reversible interhalogen bonds enabled rechargeable Li-Cl2 battery opens a new avenue to develop halogen compound cathodes.