Owing to their high volumetric capacity, reasonably low redox potential, and budget friendliness, manganese metal batteries (MnMBs) are excellent candidates for batteries with a high energy -to -price ratio. However, since there is no suitable electrolyte ensuring reversible Mn plating/stripping due to the low redox potential of the Mn 2+ /Mn redox couple and the strong interaction between charge -dense Mn 2+ ions and solvents, the development of MnMBs has been largely constrained. Herein, a halogen -mediated non -aqueous electrolyte (HM-NAE) is developed to enable highly reversible Mn plating/stripping. Benefiting from this halogen -mediated mechanism, the asymmetric Mn cell can cycle stably more than 1,000 h with a Coulombic efficiency close to 100%. Moreover, a Mn|HM-NAE|Mo 6 S 8 full cell with high electrochemical performances is constructed and fully understood. This work offers a new avenue to the development of rechargeable, non -aqueous MnMB through electrolyte engineering, which can also shed light on other multivalent metal batteries and electroplating industry.

Vanadium oxide has been extensively studied as a host of zinc ion intercalation but still suffers from low conductivity, dissolution, and byproduct accumulation during cycling. Here, we hydrothermally synthesize the VO2@MXene Ti3C2 (MV) composite and find that in the MV//3 M Zn(CF3SO3)2//Zn system, the double hydroxide Zn12(CF3SO3)9(OH)15·nH2O (ZCOH) uniformly covers VO2 during the charging process and dissolves reversibly during the discharge process. In situ X-ray diffraction of the MV combined with in situ pH measurements reveals that ZCOH acts as a pH buffer during cycling, which is beneficial to the cycling stability of batteries. And the theoretical calculation indicates that the decomposition energy required by ZCOH on the MV surface is lower than that on pure VO2, which is more conducive to ZCOH dissolution. The coin battery exhibits high-rate performance of 65.1% capacity retention at a current density of 15 A g-1 (compared to 0.6 A g-1) and a long cycling life of 20,000 cycles with a capacity retention of 80.7%. For a 22.4 mA h soft-packaged battery, its capacity remains at 72.1% after 2000 cycles. This work demonstrates the active role of ZCOH in the electrochemical process of VO2 and provides a new perspective for exploiting this mechanism to develop high-performance aqueous zinc-ion battery vanadium oxide cathode materials.

Developing facile and economical strategies to fabricate nitrogen-doped porous carbon anode is desirable for dual-carbon potassium ion hybrid capacitors (PIHCs). Here, a high-concentration edge-nitrogen-doped porous carbon (NPC) anode is synthesized by a template-free strategy, in which the total content of pyrrolic nitrogen and pyridinic nitrogen accounts for more than 80% of the nitrogen atoms. As a result, the NPC anode displays a capacity of 315.4 mA h g −1 at a current rate of 0.1 A g −1 and 189.1 mA h g −1 at 5 A g −1 . Ex situ characterizations and density functional theory calculations demonstrate the high-concentration edge-nitrogen doping enhances K + adsorption and electronic conductivity of carbon materials, resulting in good electrochemical performance. The assembled NPC//CMK-3 PIHC delivers an energy density of 71.1 W h kg −1 at a power density of 771.9 W kg −1 over 8,000 cycles.

Developing facile and economical strategies to fabricate nitrogen-doped porous carbon anode is desirable for dual-carbon potassium ion hybrid capacitors (PIHCs). Here, a high-concentration edge-nitrogen-doped porous carbon (NPC) anode is synthesized by a template-free strategy, in which the total content of pyrrolic nitrogen and pyridinic nitrogen accounts for more than 80% of the nitrogen atoms. As a result, the NPC anode displays a capacity of 315.4 mA h g−1 at a current rate of 0.1 A g−1 and 189.1 mA h g−1 at 5 A g−1. Ex situ characterizations and density functional theory calculations demonstrate the high-concentration edge-nitrogen doping enhances K+ adsorption and electronic conductivity of carbon materials, resulting in good electrochemical performance. The assembled NPC//CMK-3 PIHC delivers an energy density of 71.1 W h kg−1 at a power density of 771.9 W kg−1 over 8,000 cycles.

Graphite has been extensively employed as commercial anode material in Li-ion batteries due to its high abundance, low cost, and negative electrode potential. Furthermore, it has demonstrated significant potential for use in K-ion batteries. However, distinct structural damage caused by the larger radius of K-ion (0.138 nm) compared to that of Li-ion (0.076 nm) leads to obvious capacity decay and unstable cycle life. It is crucial to improve the cycling stability of graphite in potassium ion batteries (PIBs). Herein, we design a stable interface of graphite anode by graphene coating with a simple and efficient microwave method. According to X-ray photoelectron spectroscopy (XPS), microwave reduction can effectively remove the oxygen group of graphene oxide (GO) within 10 s. The graphene coating can buffer the volume expansion of the graphite to suppress structural collapse; it can also accelerate electronic transmission to improve rate performance. As a result, the graphene-coating graphite anode, named GCG, exhibits super cycling stability with a capacity of 262 mAh center dot g(-1) after 3000 cycles at a current density of 0.2 A center dot g(-1), which means it can operate smoothly for one year. In contrast, at the same current density, graphite exhibits capacity fading to less than 150 mAh center dot g(-1) after 150 cycles. Moreover, compared to graphite, GCG demonstrates better rate performance achieving a capacity of 161.2 mAh center dot g(-1) at 500 mA center dot g(-1). Further electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) tests show that GCG exhibits faster electrical conductivity and ion diffusion compared to graphite. Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) images after cycling verify that the graphene buffer interface benefits the integrity of the electrode structure and improves the stability of the solid electrolyte interphase (SEI). Compared to graphite, the GCG anode exhibits better performance, as follows: 1) The graphene coating inhibits exfoliation of graphite during cycling, solving the problem of graphite anode' short cycling life, and 2) the graphene protective layer improves the ion diffusion rate, resulting in better rate performance of the GCG. In addition, this approach offers the advantages of simple operation and low cost, hopefully enabling large-scale applications of potassium-ion batteries.

The utilization of MnO2/Mn2+ chemistry in near-neutral pH acetate aqueous electrolytes provides an opportunity to achieve a higher energy density (theoretical capacity 616 mA h/g, discharge platform >1.5 V). However, this Zn-MnO2 aqueous battery suffers from inevitable "dead Mn" and proton corrosion. In this study, we discover that the diffusion of the cathode reaction intermediate Mn3+ is intrinsic for the generation of "dead Mn", and the accumulation of "dead Mn" increases the H+ which shuttles to the anode, inducing serious corrosion. A pH-neutral hydrogel ion-anchored strategy is proposed here not only to restrict the diffusion of Mn3+ but also to suppress the proton transference. This hydrogel ion anchor is designed by deprotonating a series of monomers undergoing in situ free radical polymerization at the cathode interface. The anionic monomer with a moderate binding energy to manganese ions is screened to anchor Mn3+, which enhances the reversibility of the MnO2/Mn2+ reaction. Simultaneously, a substantial amount of anionic groups and hydrophilic functional groups in the hydrogel effectively constrains the proton shuttle to corrode the anode. Consequently, the Zn/MnO2 battery achieves exceptional cyclic stability of the MnO2/Mn2+ reaction, sustaining 8500 cycles even at a relatively low current density and discharge current density of 1 mA/cm2. Our findings highlight the importance of anchoring Mn3+ at the cathode interface and offer valuable insights for advancing practical applications of MnO2/Mn2+ reactions.

Sodium-ion batteries (SIBs) as one of the promising alternatives to lithium-ion batteries have achieved remarkable progress in the past. However, the all-climate performance is still very challenging for SIBs. Herein, 15-Crown-5 (15-C-5) is screened as an electrolyte additive from a number of ether molecules theoretically. The good sodiophilicity, high molecule rigidity, and bulky size enable it to reshape the solvation sheath and promote the anion engagement in the solvated structures by molecule crowding. This change also enhances Na-ion transfer, inhibits side reactions, and leads to a thin and robust solid–electrolyte interphase. Furthermore, the electrochemical stability and operating temperature windows of the electrolyte are extended. These profits improve the electrochemical performance of SIBs in all climates, much better than the case without 15-C-5. This improvement is also adopted to μ-Sn, μ-Bi, hard carbon, and MoS 2 . This work opens a door to prioritize the potential molecules in theory for advanced electrolytes.

The porous structure of SiO particles provide abundant diffusion channels for lithium ions and the outer TiO2−x favor the generation of stable SEI layer, ensuring the superb electrochemical performance of porous SiO/TiO2−x composites.

Organic electrode materials (OEMs) are emerging green power because of the promising advantages such as environmental friendliness, abundant sources, easy recycling, and structural diversity. However, several inherent issues, including low electronic conductivity, dissolution of active materials, and particle pulverization restrict their practical application. MXene, as a novel 2D material has exhibited enormous potential to solve the issues of OEMs due to its high conductivity, unique structure, exceptional mechanical property, and abundant surface groups. Up to now, various effective strategies have been presented and achieved positive effects, such as constructing heterojunction structures, in situ assembly, dip-coating, preparing free-standing MXene paper, etc. Nonetheless, comprehensive review of the progress and status is rare. Herein, an overview of the application of MXene in organic electrode materials for rechargeable batteries is systematically put forward. Meanwhile, recent progress and future development directions are presented. This review can serve as a guide for future research.

As one of most prospective anode materials of aqueous batteries, Zn metal faces severe electrolyte corrosion and fatal dendrite growth. To address these issues, the electrolyte/Zn interface needs to be carefully engineered. Here, a dense and robust layer of polysilane functionalized by-NH2 is coated on Zn in a new way. In this layer,-NH2 provides adequate alkalinity and important interaction with Zn2+, enhancing the hydrolysis and regulating the Zn2+ flux. Propyl groups increase the flexibility to buffer inevitable strain/stress and the hydrophobicity to reduce the permeation of water. Si-O-Zn enables the durable interface between Zn and this layer. These results lead to superior mechanical property, suppressed side reactions and uniform plating/stripping. Hence, it shows excellent electrochemical performance,-300 hours at 20 mA cm-2 for 10 mAh cm-2 (Depth of Discharge-57%) in symmetrical cells, and average Coulombic efficiency of 99.8% during 800 cycles for 3 mAh cm-2 in asym-metrical cells. Even at a high loading of MnO2, a small N/P ratio and a limited electrolyte, the full cells coupled still display a capacity of-2.93 mAh cm-2 after 100 cycles at 0.5 C.

Lithium-oxygen batteries (LOBs) have been developed because of their high theoretical energy density. However, both the dendrite/passivation problem of the anode and the sluggish ORR/OER kinetics of the cathode impede the improvement of batteries. Herein, N-doped CoO nanoarrays grown on carbon cloth (N-CoO/CC) are devel-oped as a free-standing matrix for both improved anode and cathode of LOBs. The superior lithiophilicity and unique three-dimensional structure of the lithium-infused N-CoO/CC composite anode (Li@N-CoO/CC) can regulate Li plating/stripping behavior and suppress lithium dendrite, achieving a cycle lifespan of more than 2500 h in a symmetrical Li metal battery (1 mA cm-2, 1 mAh cm-2). In addition, the Li@N-CoO/CC anode alleviates it from corrosion of water/oxygen to some extent in Li-O2 batteries due to the Li2CO3-riched SEI formed after cycling. Moreover, N-doped CoO nanoarrays can catalyze the formation/decomposition of amor-phous Li2O2, featuring a decreased overpotential. Based on the optimized dual electrodes, the resultant Li-O2 battery can maintain 200 cycles at 0.1 mA cm-2 within 0.25 mAh cm-2.

Rechargeable aqueous zinc-ion batteries (ZIBs) are the prospective substitution for lithium-ion batteries applied in large scale energy storage system due to their low-cost, environmentally friendliness, and high safety. How-ever, the development of cathodes in aqueous ZIBs suffers from sluggish Zn2+ migration. Herein, nitrogen doped V2O5 is introduced to resolve the above problem. N-doping lowers the bandgap energy of V(2)O(5 )to improve its electronic conductivity, and weakens the forces between Zn2+ and V2O5 to fasten Zn2+ diffusion. Further density functional theory (DFT) calculation testifies that N-doping reduces diffusion energy barrier and changes Zn2+ diffusion pathway from the vertical interlayer diffusion to planer intralayer diffusion. Meanwhile, the structural stability of electrode material also benefits from the N-doping, which can prevent the interlayer V2O5 from gliding or exfoliation during cycling. Profiting from these merits, N-doping V2O5 exhibits the outstanding electrochemical properties, such as high rate capability (116.8 mAh/g at 6 A/g) and long cycling performance (3000 cycles at 10 A/g). Dynamics and post-cycling analyses reveal the high capacitive ratio and the stable N distribution in N-doped V2O5 during charging/discharging.

Novel sandwich-like porous carbon nanosheet-supported hexagonal carbon micro-flakes (WPWMC) are fabricated via a one-step hydrothermal route at 700 °C with polyethylene as the precursor and magnesium as the inducer. Through various characterizations, it is confirmed that the hexagonal carbon micro-flakes exhibit (002) orientation, which exposes abundant edge active sites and shortens the K+ transmission path. Moreover, the inside cross-linked carbon nanosheets with abundant pores can accelerate ion diffusion and increase the capacitive contribution. The WPWMC anode displays a high reversible capacity (528.7 mA h g-1 at 0.2 A g-1), good rate capability (152.7 mA h g-1 at 10 A g-1) and long-term cycle stability (112.1 mA h g-1 at 5 A g-1 after 10 000 cycles). Furthermore, the WPWMC//CMK-3 hybrid capacitor exhibits an energy density of 222.7 W h kg-1 at 446.2 W kg-1. This work provides an idea for transforming waste plastic into value-added materials.

Phase boundaries facilitate the charge transportation and alleviate the intrinsic stress upon cycles.Therefore, how to achieve regular phase boundaries is very attractive. Herein, dimer-like Sn-Bi@C nanostructures, where is a well-defined phase boundary between Sn and Bi, have been prepared by a two-step process for the first time. The phase boundary not only provides additional and fast transportation for Na+, but also mitigates the structure stress/strain upon cycling. Therefore, Sn-Bi@C exhibits a high capacity(472.1 m A h g -1 at 2 A g -1 for 200 cycles), an ultra-long cyclic life(355.6 mA h g -1 at 5 A g -1 for 4500cycles) and an excellent rate performance(372 mA h g -1 at 10 A g -1 ) for sodium storage, much higher than those of Sn@C, Bi@C, and Sn@C + Bi@C. Notably, the full cells of Sn-Bi@C//Na 3 V 2 （PO 4 ） 3 /rGO（SnBi@C//NVP/rGO） demonstrate impressive performance(323 mA h g -1 at 2 A g -1 for 300 cycles). The underlying mechanism for such an excellent performance is elucidated by in-situ X-ray diffraction, exsitu scanning electron microscopy/high-resolution transmission electron microscopy and atomic force microscopy, revealing the good electrode stability and improved mechanical properties of Sn-Bi@C.The synthetic method is extended to dimer-like Sn-Pb@C and Sn-Ag@C heterostructures, which also exhibit the good cycle stability for sodium storage.

Herein, a chemical pre-potassiation strategy via simultaneously treating both glucose derived carbon (GDC) anode and commercial activated carbon (CAC) cathode in potassium-naphthalene-tetrahydrofuran solution is developed for potassium ion hybrid capacitor (PIHC). Combined with in situ and ex situ characterizations, a radical reaction between pre-potassiation reagent and carbon electrodes is confirmed, which not only deactivates electrochemical irreversible sites, but also promotes to pre-form a uniform and dense KF-rich electrolyte film on the electrodes. As a result, the pre-potassiation treatment presents multiple advantages: (I) the initial Coulombic efficiency (CE) of the GDC anode increases from 45.4 % to 84.0 % with higher rate capability; (II) the CAC cathode exhibits the improved cycling CEs and stability due to the enhanced resistance to electrolyte oxidation at 4.2 V; (III) the assembled PIHC achieves a high energy density of 172.5 Wh kg(-1) with cycling life over 10000 cycles.

Aqueous zinc metal batteries are limited in practical applications due to their short lifespans. Herein, a LaF3-coated Zn anode (LF@Zn) is investigated to induce the uniform Zn deposition and successfully build a separator-free quasi-solid-state zinc metal battery. The LF@Zn enables smooth and dendrite-free Zn deposition, owing to the homogeneous Zn2+ flux regulated by the LaF3-based quasi-solid-state electrolyte. It can also suppress the corrosion side reactions by modulating the [Zn(H2O)6]2+ solvation sheath. The polarization of plating and stripping is relatively modest due to the reduced diffuse energy of desolvated Zn2+ in the quasi-solid-state electrolyte. In a separator-free symmetric cell, the LF@Zn anode shows a significantly prolonged lifespan of over 1300 h at 2 mA cm-2 and a superior rate performance with only 156 mV at an ultrahigh current density of 50 mA cm-2. A LF@Zn//VO2 quasi-solid-state full cell exhibits outperforming rate capability and a long cyclic performance for up to 3000 cycles at 6.0 A g-1. A stable Zn anode is established in this work with a fluoride-based quasi-solid-state electrolyte, opening up a new avenue for protecting metal anodes.

Regulating lithium deposition/stripping behavior in 3D hosts is critical for the development of stable lithium metal batteries. Herein, a low‐tortuosity wood derived carbon (WDC) with gradient‐distributed lithiophilic sites is rationally constructed via biomimetic capillary action, as an efficient scaffold for lithium deposition/stripping. Due to the merits of excellent spatial controllability, the gradient Ag particles modified WDC (WDC‐GDAg) displays favorable bottom‐up Li plating behavior with high columbic efficiency and long cycling stability. Finite element simulation reveals that gradient‐distributed Ag sites enable high lithium flux distribution at the bottom and homogeneous electric field distribution on the top of the WDC electrode. Moreover, the full cells with a WDC‐GDAg anode and a LiFePO 4 cathode demonstrate high capacity retention of ≈78.9% after 2000 cycles at 10 C and remarkable rate performance even at 40 C, presenting great potential for practical applications.

Stable Zn anodes with a high utilization efficiency pose a challenge due to notorious dendrite growth and severe side reactions. Therefore, electrolyte additives are developed to address these issues. However, the additives are always consumed by the electrochemical reactions over cycling, affecting the cycling stability. Here, hexamethylphosphoric triamide (HMPA) is reported as an electrolyte additive for achieving stable cycling of Zn anodes. HMPA reshapes the solvation structures and promotes anion decomposition, leading to the in situ formation of inorganic-rich solid-electrolyte-interphase. More interestingly, this anion decomposition does not involve HMPA, preserving its long-term impact on the electrolyte. Thus, the symmetric cells with HMPA in the electrolyte survive ≈500 h at 10 mA cm −2 for 10 mAh cm −2 or ≈200 h at 40 mA cm −2 for 10 mAh cm −2 with a Zn utilization rate of 85.6 %. The full cells of Zn||V 2 O 5 exhibit a record-high cumulative capacity even under a lean electrolyte condition (E/C ratio=12 μL mAh −1 ), a limited Zn supply (N/P ratio=1.8) and a high areal capacity (6.6 mAh cm −2 ).

Cu-based cathodes in aqueous batteries become very attractive in view of high theoretical capacity,mod-erate operation voltage and rich reserves of raw materials.However,their applications are obstructed by serious side reactions.The side reaction mainly arises from the spontaneous formation of Cu2O,which occupies the electrode surface and lowers the reaction reversibility.Here,Na2EDTA is introduced to address these issues.Both experimental results and theoretical calculations indicate that the Na2EDTA reshapes the solvation structure of Cu2+and modifies the electrode/electrolyte interface.Therefore,the redox potential of Cu2+/Cu2O is reduced and the surface of Cu is protected from H2O,thereby inhibiting the formation of Cu2O.Meanwhile,the change in the solvation structure reduces the electrostatic repul-sion between Cu2+and the cathode,leading to high local concentration and benefiting uniform deposi-tion.The results shed light on the applications of rechargeable Cu-based batteries.

Herein, a pressure-dependent self-template pyrolysis strategy is developed to modulate the porosity and surface chemical configuration of carbon electrodes (MPCs) for dual-carbon potassium ion hybrid capacitors (PIHCs). Experiments demonstrate that negative pyrolysis pressure (delta P =-0.1 MPa) can restrict the growth of templates in the carbon matrix and accelerate surface oxygen removal, contributing to a large surface area of 2383.6 m(2) g(-1 )with abundant micropores for high adsorption capacity and low surface oxygen content for good compati-bility with the electrolyte at high voltage as cathodes. Relatively, positive pressure (delta P = 10.0 MPa) prevents the escape of pyrolysis gas which would in turn re-react with the self-generated templates, thereby forming hierarchical macroporous structure composed of interconnected carbon nanosheets and nanoparticles for high -rate capabilities as anodes. As a result, NPC cathodes exhibit high capacity of 63.7 mA h g(-1) after 8000 cy-cles at 2.0 A g(-1), while PPC anodes deliver high capacity of 258.8 mA h g(-1) with capacity retention of 93.5 % after 10,000 cycles at 5.0 A g(-1). The assembled PPC//NPC PIHCs also exhibit high energy density of 172.8 Wh kg(-1) at 223.1 W kg-1, with long-term cycling stability over 10,000 cycles at 1.0 A g-1 or 2.0 A g(-1).