Progress in aqueous rechargeable batteries

Over the past decades, a series of aqueous rechargeable batteries(ARBs) were explored, investigated and demonstrated. Among them,aqueous rechargeable alkali-metal ion(Li^+Na^+, K^+) batteries, aqueous rechargeable-metal ion(Zn^(2+),Mg^(2+), Ca^(2+), Al^(3+)) batteries and aqueous rechargeable hybrid batteries are standing out due to peculiar properties. In this review, we focus on the fundamental basics of these batteries, and discuss the scientific and/or technological achievements and challenges. By critically reviewing state-of-the-art technologies and the most promising results so far, we aim to analyze the benefits of ARBs and the critical issues to be addressed, and to promote better development of ARBs.

A phenazine anode for high-performance aqueous rechargeable batteries in a wide temperature range

Aqueous rechargeable batteries are a possible strategy for large-scale energy storage systems.However,limited choices of anode materials restrict their further application.Here we report phenazine(PNZ)as stable anode materials in different alkali-ion(Li+,Na+,K+)electrolyte.A novel full cell is assembled by phenazine anode,Na0.44MnO2 cathode and 10 M NaOH electrolyte to further explore the electrochemical performance of phenazine anode.This battery is able to achieve high capacity(176.7 mAh·g^−1 at 4 C(1.2·Ag^−1)),ultralong cycling life(capacity retention of 80%after 13,000 cycles at 4 C),and excellent rate capacity(92 mAh·g^−1 at 100 C(30 A·g^−1)).The reaction mechanism of PNZ during charge—discharge process is demonstrated by in situ Raman spectroscopy,in situ Fourier transform infrared(FTIR)spectroscopy,X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT)calculations.Furthermore,the system is able to successfully operate at wide temperature range from−20 to 70°C and achieves remarkable electrochemical performance.

Latest Advances in High-Voltage and High-Energy-Density Aqueous Rechargeable Batteries

Aqueous rechargeable batteries(ARBs)have become a lively research theme due to their advantages of low cost,safety,environmental friendliness,and easy manufacturing.However,since its inception,the aqueous solution energy storage sys-tem has always faced some problems,which hinders its development,such as the narrow electrochemical stability window of water,poor percolation of electrode materials,and low energy density.In recent years,to overcome the shortcomings of the aqueous solution-based energy storage system,some very pioneering work has been done,which also provides a great inspiration for further research and development of future high-performance aqueous energy storage systems.In this paper,the latest advances in various ARBs with high voltage and high energy density are reviewed.These include aqueous rechargeable lithium,sodium,potassium,ammonium,zinc,magnesium,calcium,and aluminum batteries.Further chal-lenges are pointed out.

Reinventing the mechanism of high-performance Bi anode in aqueous K^+ rechargeable batteries

Increasing attention has been paid to rechargeable aqueous batteries due to their high safety and low cost.However,they remain in their infancy because of the limited choice of available anode materials with high specific capacity and satisfying cycling performance.Bi metal with layered structure can act as an ideal anode material with high capacity;however,the energy storage mechanism has not well elucidated.Herein,we demonstrate that Bi metal enables affording ultra-high specific capacity(254.3 mAh g^-1),superior rate capability and a capacity retention of 88.8%after 1600 cycles.Different from the previously-reported redox reaction mechanisms of Bi electrode,efficient(de)alloying of K+is responsible for its excellent performance.An excellent aqueous Bi battery is fabricated by matching Bi anode with Co(OH)2 cathode in KOH(1 M)electrolyte.Its outstanding performance is quite adequate and competitive for electrochemical energy storage devices.

Universal organic anodes enable safe low-cost aqueous rechargeable batteries with long cycle life,high capacity, and fast kinetics

Future battery advances and economies of scale will help scrub CO2emissions from transportation and the grid.Economical energy storage lets battery-powered electric vehicles replace internal combustion engines in the transportation sector,which now accounts for the plurality of CO2emissions.For grid-scale applications,the benefits of adding storage are many and well documented[1–2].Beyond increased penetration of intermittent renewable energy generated from such as solar panels

Key materials and future perspective for aqueous rechargeable lithium-ion batteries

Aqueous rechargeable lithium-ion battery(ARLiB)is of specific importance due to the low-cost,environmentalfriendly properties.Recently,its energy denisty and cyclic life have been significantly enhanced,demonstarting the potential for real applications.The improvement on key materials of ARLiB,ranging from cathode,anode and electrolyte,can finally ameliorate coresponding performance of full cell.Hereon,the cathode materials of ARLiBs are summerized as spinel oxides,layered oxides,olivine polyanion compounds olivine and Prussian blue analogues,while anode materials are classified into vanadium-based,polyanion,titanium-based and organic ones.Meanwhile,the strategies for better aqueous electrolytes are discussed from the aspects of salt concentration,solvent and interface.In the last part,issues challenging the commercialization of ARLiBs are provided as well as the suggestions for future research and development.

Recent advances in energy storage mechanism of aqueous zinc-ion batteries

Aqueous rechargeable zinc-ion batteries(ZIBs)have recently attracted increasing research interest due to their unparalleled safety,fantastic cost competitiveness and promising capacity advantages compared with the commercial lithium ion batteries.However,the disputed energy storage mechanism has been a confusing issue restraining the development of ZIBs.Although a lot of efforts have been dedicated to the exploration in battery chemistry,a comprehensive review that focuses on summarizing the energy storage mechanisms of ZIBs is needed.Herein,the energy storage mechanisms of aqueous rechargeable ZIBs are systematically reviewed in detail and summarized as four types,which are traditional Zn^(2+)insertion chemistry,dual ions co-insertion,chemical conversion reaction and coordination reaction of Zn^(2+)with organic cathodes.Furthermore,the promising exploration directions and rational prospects are also proposed in this review.

Toward stable and highly reversible zinc anodes for aqueous batteries via electrolyte engineering

Featuring low cost, high abundance, low electrochemical potential, and large specific capacity, zinc(Zn)metal holds great potential as an anode material for next-generation rechargeable aqueous batteries.However, the poor reversibility resulting from dendrite formation and side reactions poses a major obstacle for its practical application. Electrolyte, which is regarded as the “blood” of batteries, has a direct impact on reaction kinetics, mass transport, and side reactions and thus plays a key role in determining the electrochemical performance of Zn electrodes. Therefore, considerable efforts have been devoted to modulating the electrolytes to improve the performance of Zn electrodes. Although significant progress has been made, achieving stable and highly reversible Zn electrodes remains a critical challenge. This review aims to provide a systematic summary and discussion on electrolyte strategies for highperformance aqueous Zn batteries. The(electro)-chemical behavior and fundamental challenges of Zn electrodes in aqueous electrolytes are first discussed. Electrolyte modulation strategies developed to address these issues are then classified and elaborated according to the underlying mechanisms.Finally, remaining challenges and promising future research directions on aqueous electrolyte engineering are highlighted. This review offers insights into the design of highly efficient electrolytes for new generation of rechargeable Zn batteries.

MnO Stabilized in Carbon-Veiled Multivariate Manganese Oxides as High-Performance Cathode Material for Aqueous Zn-Ion Batteries

Aqueous Zn-ion battery has emerged as one of the most prospective energy storage devices due to its low cost,high safety,and eco-friendliness.However,Zn-ion batteries are bottlenecked by significant capacity fading during long-term cycling and poor performance at high current rates.Here,we report an available cooperation of multivariate manganese oxides@carbon hybrids(MnO_(2)/MnO@C and MnO_(2)/Mn_(3)O_(4)@C)via a plasma-assisted design as an attractive Zn-ion cathode.Among them,the MnO_(2)/MnO@C cathode exhibits a reversible specific capacity of 165 m Ah g^(-1)over 200 cycles at a high rate of 0.5 A g^(-1),and possesses great rate performance with high capacities of 110 and 100 m Ah g^(-1)at a high rate of 0.8 and 1 A g^(-1),respectively.The good cathode performance significantly results from the facile charge transfer and ions(Zn^(2+)and H^(+))insertion in the manganese oxides/carbon hybrids featuring phase stability behavior in the available cooperation of multivalence and carbon conductive substrates.This work will promote the Zn-manganese dioxide system for the design of low-cost and high-performance aqueous rechargeable Zn-ion batteries.

A Sustainable Dual Cross‑Linked Cellulose Hydrogel Electrolyte for High‑Performance Zinc‑Metal Batteries

Aqueous rechargeable Zn-metal batteries(ARZBs)are considered one of the most promising candidates for grid-scale energy storage.However,their widespread commercial application is largely plagued by three major challenges:The uncontrollable Zn dendrites,notorious parasitic side reactions,and sluggish Zn^(2+) ion transfer.To address these issues,we design a sustainable dual crosslinked cellulose hydrogel electrolyte,which has excellent mechanical strength to inhibit dendrite formation,high Zn^(2+) ions binding capacity to suppress side reaction,and abundant porous structure to facilitate Zn^(2+) ions migration.Consequently,the Zn||Zn cell with the hydrogel electrolyte can cycle stably for more than 400 h under a high current density of 10 mA cm^(−2).Moreover,the hydrogel electrolyte also enables the Zn||polyaniline cell to achieve high-rate and long-term cycling performance(>2000 cycles at 2000 mA g^(−1)).Remarkably,the hydrogel electrolyte is easily accessible and biodegradable,making the ARZBs attractive in terms of scalability and sustainability.

In-situ oriented oxygen-defect-rich Mn-N-O via nitridation and electrochemical oxidation based on industrial-scale Mn_(2)O_(3) to achieve high-performance aqueous zinc ion battery

As a general problem in the field of batteries,materials produced on a large industrial scale usually possess unsatisfactory electrochemical performances.Among them,manganese-based aqueous rechargeable zinc-ion batteries(ARZBs)have been emerging as promising large-scale energy storage systems owing to their high energy densities,low manufacturing cost and intrinsic high safety.However,the direct application of industrial-scale Mn2O3(MO)cathode exhibits poor electrochemical performance especially at high current rates.Herein,a highly reversible Mn-based cathode is developed from the industrial-scale MO by nitridation and following electrochemical oxidation,which triples the ion diffusion rate and greatly promotes the charge transfer.Notably,the cathode delivers a capacity of 161 m Ah g^(-1) at a high current density of 10 A g^(-1),nearly-three times the capacity of pristine MO(60 m Ah g^(-1)).Impressive specific capacity(243.4 m Ah g^(-1))is obtained without Mn^(2+) additive added in the electrolyte,much superior to the pristine MO(124.5 m Ah g^(-1)),suggesting its enhanced reaction kinetics and structural stability.In addition,it possesses an outstanding energy output of 368.4 Wh kg^(-1) at 387.8 W kg^(-1),which exceeds many of reported cathodes in ARZBs,providing new opportunities for the large-scale application of highperformance and low-cost ARZBs.

Ultrahigh-energy and-power aqueous rechargeable zinc-ion microbatteries based on highly cation-compatible vanadium oxides

Aqueous multivalent-metal-ion intercalation chemistries hold genuine promise to develop safe and powerful microbatteries for potential use in many miniaturized electronics.However,their development is beset by state-of-the-art electrode materials having practical capacities far below their theoretical values.Here we demonstrate that high compatibility between layered transition-metal oxide hosts and hydrated cation guests substantially boost their multi-electron-redox reactions to offer higher capacities and rate capability,based on typical bipolar vanadium oxides preintercalated with hydrated cations(M_(x)V_(2)O_(5)).When seamlessly integrated on Au current microcollectors with a three-dimensional bicontinuous nanoporous architecture that offers high pathways of electron transfer and ion transport,the constituent Zn_(x)V_(2)O_(5) exhibits specific capacity of as high as∼527 mAh g^(−1) at 5 mV s^(−1) and retains∼300 mAh g^(−1) at 200 mV s^(−1) in 1 M ZnSO_(4) aqueous electrolyte,outperforming the M_(x)V_(2)O_(5)(M=Li,Na,K,Mg).This allows aqueous rechargeable zinc-ion microbatteries constructed with symmetric nanoporous Zn_(x)V_(2)O_(5)/Au interdigital microelectrodes as anode and cathode to show high-density energy of∼358 mWh cm^(−3)(a value that is forty-fold higher than that of 4 V/500μAh Li thin film battery)at high levels of power delivery.

Stable interphase chemistry of textured Zn anode for rechargeable aqueous batteries

Despite the advances of aqueous zinc(Zn)batteries as sustainable energy storage systems,their practical application remains challenging due to the issues of spontaneous corrosion and dendritic deposits at the Zn metal anode.In this work,conformal growth of zinc hydroxide sulfate(ZHS)with dominating(001)facet was realized on(002)plane-dominated Zn metal foil fabricated through a facile thermal annealing process.The ZHS possessed high Zn^(2+)conductivity(16.9 mS cm^(-1))and low electronic conductivity(1.28×10^(4)Ωcm),and acted as a heterogeneous and robust solid electrolyte interface(SEI)layer on metallic Zn electrode,which regulated the electrochemical Zn plating behavior and suppressed side reactions simultaneously.Moreover,low self-diffusion barrier along the(002)plane promoted the 2D diffusion and horizontal electrochemical plating of metallic Zn for(002)-textured Zn electrode.Consequently,the as-achieved Zn electrode exhibited remarkable cycling stability over 7000 cycles at 2 mA cm^(-2)and 0.5 mAh cm^(-2)with a low overpotential of 25 mV in symmetric cells.Pairing with a MnO_(2)cathode,the as-achieved Zn electrode achieved stable cell cycling with 92.7%capacity retention after 1000 cycles at 10 C with a remarkable average Coulombic efficiency of 99.9%.

Aqueous Zn-based rechargeable batteries:Recent progress and future perspectives

Benefiting from the advantageous features of high safety,abundant reserves,low cost,and high energy density,aqueous Zn-based rechargeable batteries(AZBs)have received extensive attention as promising candidates for energy storage.To achieve high-performance AZBs with high reversibility and energy density,great efforts have been devoted to overcoming their drawbacks by focusing on the modification of electrode materials and electrolytes.Based on different cathode materials and aqueous electrolytes,the development of aqueous AZBs with different redox mechanisms are discussed in this review,including insertion/extraction chemistries(e.g.,Zn^(2+),alkali metal ion,H^(+),NH_(4)^(+),and so forth dissolution/deposition reactions(e.g.,MnO_(2)/Mn^(2+)),redox couples in flow batteries(e.g.,I_(3)/3I,Br_(2)/Br,and so forth),oxygen electrochemistry(e.g.,O_(2)/OH,O_(2)/O_(2)2),and carbon dioxide electrochemistry(e.g.,CO_(2)/CO,CO_(2)/HCOOH).In particular,the basic reaction mechanisms,issues with the Zn electrode,aqueous electrolytes,and cathode materials as well as their design strategies are systematically reviewed.Finally,the remaining challenges faced by AZBs are summarized,and perspectives for further investigations are proposed.

Boosting Zn-ion storage capability of self-standing Zn-doped Co_(3)O_(4)nanowire array as advanced cathodes for high-performance wearable aqueous rechargeable Co//Zn batteries

Neutral aqueous rechargeable Co_(3)O_(4)//Zn batteries with high-output voltage and outstanding cycling stability have yielded new insights into wearable energy-storage devices.To meet the increasing demand for a means of powering wearable and portable devices,the development of a high-performance fiber-shaped Co//Zn battery would be highly desirable.However,the intrinsically poor conductivity of C 03O4 significantly restricts the application of these high-capacity and high-rate aqueous rechargeable battery.Encouragingly,density functional theory(DFT)calculations demonstrate that the substitution of Zn for Co^(3+)leads to an insulatormetal transition in the Zn-doped Co_(3)O_(4)(Zn-Co_(3)O_(4)).In this study,we used metallic Zn-Co_(3)O_(4)nanowire arrays(NWAs)as a novel binder-free cathode to successfully fabricate an all-solid-state fiber-shaped aqueous rechargeable(AFAR)Co//Zn battery.The resulting fiber-shaped Co//Zn battery takes advantage of the enhanced conductivity,increased capacity,and improved rate capability of Zn-Co_(3)O_(4)NWAs to yield a remarkable capacity of 1.25 mAh·cm^(-2)at a current density of 0.5 mA·cm^(-2),extraordinary rate capability(60.8%capacity retention at a high current density of 20 mA·cm^(-2))and an admirable energy density of 772.6 mWh·cm^(-3).Thus,the successful construction of Zn-Co_(3)O_(4)NWAs provides valuable insights into the design of high-capacity and high-rate cathode materials for aqueous rechargeable high-voltage batteries.

Novel aqueous rechargeable nickel//bismuth battery based on highly porous Bi_(2)WO6 and Co_(0.5)Ni_(0.5)MoO_(4) microspheres

Developing high performances aqueous rechargeable batteries is imperative and valuable.Herein,a novel aqueous rechargeable nickel//bismuth battery is developed based on highly porous Bi_(2)WO_(6) and Co_(0.5)Ni_(0.5)MoO_(4) microspheres as electrode active materials.Porous Bi_(2)WO6 microspheres assembled from nanosheets as anode active materials can afford a specific capacity of179.2 mAh·g^(-1) at 1 A·g^(-1),rate capability of 74.7%in 1-20 A·g^(-1),and capacity retention of 57.2%for 1500 cycles at 15 A·g^(-1).Owing to the highly porous microsphere with’ribbon’-like and intertwined nanolayers morphology,the screened Co0.5Ni0.5MoO4 cathode active materials present an outstanding specific surface area of 293 m^(2)·g^(-1)and excellent electrochemical performance(such as superior specific capacity of 113.2 mAh·g^(-1) at 1 A·g^(-1),high rate performance of 51.8%in 1-15 A·g^(-1),and good capacity retention of 48.5%for 4600 cycles at15 A·g^(-1)).The corresponding aqueous rechargeable nickel//bismuth battery delivers the maximum energy density and power density of 35.8 Wh·kg^(-1) and3238.5 W·kg^(-1),respectively.The present research would offer a worthwhile guidance for the effective construction of electrode active materials for aqueous rechargeable nickel//bismuth batteries.

Bipolar electrode architecture enables high-energy aqueous rechargeable sodium ion battery

Aqueous rechargeable sodium ion batteries(ARSIBs),with intrinsic safety,low cost,and greenness,are attracting more and more attentions for large scale energy storage application.However,the low energy density hampers their practical application.Here,a battery architecture designed by bipolar electrode with graphite/amorphous carbon film as current collector shows high energy density and excellent rate-capability.The bipolar electrode architecture is designed to not only improve energy density of practical battery by minimizing inactive ingredient,such as tabs and cases,but also guarantee high rate-capability through a short electron transport distance in the through-plane direction instead of in-plane direction for traditional cell architecture.As a proof of concept,a prototype pouch cell of 8 V based on six Na_(2)MnFe(CN)_(6)||NaTi_(2)(PO_(4))_(3)bipolar electrodes stacking using a“water-in-polymer”gel electrolyte is demonstrated to cycle up to 4,000 times,with a high energy density of 86 Wh·kg^(−1)based on total mass of both cathode and anode.This result opens a new avenue to develop advance high-energy ARSIBs for grid-scale energy storage applications.

Hydrated ammonium manganese phosphates by electrochemically induced manganese-defect as cathode material for aqueous zinc ion batteries

Aqueous zinc ion batteries(AZIBs) with the merits of low cost, low toxicity, high safety, environmental benignity as well as multi-valence properties as the large-scale energy storage devices demonstrate tremendous application prospect. However, the explorations for the most competitive manganese-based cathode materials of AZIBs have been mainly limited to some known manganese oxides. Herein, we report a new type of cathode material NH_(4)MnPO_(4)·H_(2)O(abbreviated as AMPH) for rechargeable AZIBs synthesized through a simple hydrothermal method. An in-situ electrochemical strategy inducing Mn-defect has been used to unlock the electrochemical activity of AMPH through the initial charge process, which can convert poor electrochemical characteristic of AMPH towards Zn^(2+)and NH_(4)+into great electrochemically active cathode for AZIBs. It still delivers a reversible discharge capacity up to 90.0 m Ah/g at 0.5 A/g even after 1000thcycles, which indicates a considerable capacity and an impressive cycle stability. Furthermore, this cathode reveals an(de)insertion mechanism of Zn^(2+)and NH_(4)+without structural collapse during the charge/discharge process. The work not only supplements a new member for the family of manganese-based compound for AZIBs, but also provides a potential direction for developing novel cathode material for AZIBs by introducing defect chemistry.

Advanced Organic Materials for Nonmetallic Charge Carrier-Based Batteries

Organic electrode materials(OEMs),withmerits of structural diversity,molecular-level controllability,resource abundance,and environmental friendliness,have become a promising electrode candidate for low-carbon renewable batteries.Safer,environmentally benign,and sustainable aqueous rechargeable batteries are particularly appealing for large-scale energy storage applications.This review aims to provide an insightful discussion of OEMs in nonmetallic charge carrier-based batteries,especially for the application in aqueous rechargeable systems.The emerging application of OEMs in versatile aqueous batteries will be analyzed emphatically,including aqueous proton batteries,aqueous ammonium-ion batteries,and air self-charging batteries.We expect that this review can serve as a guide for the future development of OEMs in nonmetallic charge carrier-based batteries and provide inspiration for unmet challenges.

High-performance Na1.25V3O8 nanosheets for aqueous zinc-ion battery by electrochemical induced de-sodium at high voltage

Aqueous rechargeable zinc-ion batteries(ARZIBs) are expected to replace organic electrolyte batteries owing to its low price,safe and environmentally friendly characteristics.Herein,we fabricated vanadium-based Na1.25V3O8 nanosheets as a cathode material for ARZIBs,which present a high performance by electrochemical de-sodium at high voltage to form Na2V6O16 phase in the first cycle:high capacity of 390 mAh/g at 0.1 A/g,high rate perfo rmance(162 mAh/g at 10 A/g) and superior cycle stability(179 mAh/g with a high capacity retention of 88.2% of the maximum capacity after 2000 cycles).In addition,the cell exhibits a high energy density of 416.9 Wh/kg at 143.6 W/kg,suggesting great potential of the as-prepared Na1.25V3O8 nanosheets for ARZIBs.