Sodium-ion batteries (SIBs) with organic electrodes are an emerging research direction due to the sustainability of organic materials based on elements like C,H,O,and sodium ions.Currently,organic electrode materials for SIBs are mainly used as cathodes because of their relatively high redox potentials(>1 V).Organic electrodes with low redox potential that can be used as anode are rare.Herein,a novel organic anode material (tetrasodium 1,4,5,8-naphthalenetetracarboxylate,Na_(4)TDC) has been developed with low redox potential (<0.7 V) and excellent cyclic stability.Its three-sodium storage mechanism was demonstrated with various in-situ/ex-situ spectroscopy and theoretical calculations,showing a high capacity of 208 mAh/g and an average decay rate of merely 0.022%per cycle.Moreover,the Na_(4)TDC-hard carbon composite can further acquire improved capacity and cycling stability for 1200 cycles even with a high mass loading of up to 20 mg cm^(-2).By pairing with a thick Na_(3)V_(2)(PO_(4))_(3)cathode (20.6 mg cm^(-2)),the as-fabricated full cell exhibited high operating voltage (2.8 V),excellent rate performance and cycling stability with a high capacity retention of 88.7% after 200 cycles,well highlighting the Na_(4)TDC anode material for SIBs.
Zhi LiYang WeiKang ZhouXin HuangXing ZhouJie XuTaoyi KongJunwei Lucas BaoXiaoli DongYonggang Wang
Potassium-ion batteries(PIBs)are considered as a promising energy storage system owing to its abundant potassium resources.As an important part of the battery composition,anode materials play a vital role in the future development of PIBs.Bismuth-based anode materials demonstrate great potential for storing potassium ions(K^(+))due to their layered structure,high theoretical capacity based on the alloying reaction mechanism,and safe operating voltage.However,the large radius of K^(+)inevitably induces severe volume expansion in depotassiation/potassiation,and the sluggish kinetics of K^(+)insertion/extraction limits its further development.Herein,we summarize the strategies used to improve the potassium storage properties of various types of materials and introduce recent advances in the design and fabrication of favorable structural features of bismuth-based materials.Firstly,this review analyzes the structure,working mechanism and advantages and disadvantages of various types of materials for potassium storage.Then,based on this,the manuscript focuses on summarizing modification strategies including structural and morphological design,compositing with other materials,and electrolyte optimization,and elucidating the advantages of various modifications in enhancing the potassium storage performance.Finally,we outline the current challenges of bismuth-based materials in PIBs and put forward some prospects to be verified.
With the increasing prevalence of lithium-ion batteries(LIBs)applications,the demand for high-capacity next-generation materials has also increased.SiO_(x)is currently considered a promising anode material due to its exceptionally high capacity for LIBs.However,the significant volumetric changes of SiO_(x)during cycling and its initial Coulombic efficiency(ICE)complicate its use,whether alone or in combination with graphite materials.In this study,a three-dimensional conductive binder network with high electronic conductivity and robust elasticity for graphite/SiO_(x)blended anodes was proposed by chemically anchoring carbon nanotubes and carboxymethyl cellulose binders using tannic acid as a chemical cross-linker.In addition,a dehydrogenation-based prelithiation strategy employing lithium hydride was utilized to enhance the ICE of SiO_(x).The combination of these two strategies increased the CE of SiO_(x)from 74%to87%and effectively mitigated its volume expansion in the graphite/SiO_(x)blended electrode,resulting in an efficient electron-conductive binder network.This led to a remarkable capacity retention of 94%after30 cycles,even under challenging conditions,with a high capacity of 550 mA h g^(-1)and a current density of 4 mA cm^(-2).Furthermore,to validate the feasibility of utilizing prelithiated SiO_(x)anode materials and the conductive binder network in LIBs,a full cell incorporating these materials and a single-crystalline Ni-rich cathode was used.This cell demonstrated a~27.3%increase in discharge capacity of the first cycle(~185.7 mA h g^(-1))and exhibited a cycling stability of 300 cycles.Thus,this study reports a simple,feasible,and insightful method for designing high-performance LIB electrodes.
Chaeyeon HaJin Kyo KooJun Myoung SheemYoung-Jun Kim
Potassium-ion batteries(PIBs)have garnered significant interest due to their abundant resources,wide distribution and low price,emerging as an ideal alternative to lithium-ion batteries for energy storage systems.As one of the key components,anode materials act as a crucial role in the specific capacity,energy density,power density and service life of PIBs,so it is highly significant to conduct a comprehensive investigation on them.Carbon materials are widely employed as the anode for PIBs because of their advantages of environmental friendliness,abundant raw materials and diverse structures.According to the structural differences,carbon materials are mainly distinguished as crystalline carbon represented by graphite and graphene,and soft carbon and hard carbon existing in amorphous state.Different types of carbon materials have special ion storage mechanisms,storage capacity and cycling stability.Herein,it is meaningful to summarize and discuss the characteristics and research progress in carbon anode materials for PIBs in recent years.Firstly,according to the development status and application prospect of graphite,graphene,soft carbon,and hard carbon,we deeply generalize the electrochemical performance and potassium storage mechanism.Then we dig out the key problems faced by different carbon materials and arrange various modification design and solving strategies of novel carbon anodes.Finally,we expound the importance of carbon anode materials as the anode and PIBs,explore the application potential of current and emerging carbon anode materials,and put forward some suggestions and prospects for the future development of carbon materials.
Zhaomeng LiuZhiqing GongKunyang HePeng QiuXuan-Chen WangLu-Kang ZhaoQin-Fen GuXuan-Wen GaoWen-Bin Luo
Unstable Zn interface caused by rampant dendrite growth and parasitic side reactions always hinders the practical application of aqueous zinc metal batteries(AZMBs),Herein,tyrosine(Tyr)with high molecular polarity was introduced into aqueous electrolyte to modulate the interfacial electrochemistry of Zn anode.In AZMBs,the positively charged side of Tyr can be well adsorbed on the surface of Zn anode to form a water-poor layer,and the exposed carboxylate side can be easily coordinated with Zn^(2+),favoring inducing uniform plating of Zn^(2+)and inhibiting the occurrence of water-induced side reactions.These in turn enable the achievement of highly stable Zn anode.Accordingly,the Zn anodes achieve outstanding cyclic stability(3000 h at 2 mA cm^(-2),2 mA h cm^(-2)and 1300 h at 5 mA cm^(-2),5 mA h cm^(-2)),high average Coulombic efficiency(99.4%over 3200 cycles),and high depth of discharge(80%for 500 h).Besides,the assembled Zn‖NaV_(3)O_(8)·1.5H_(2)O full cells deliver remarkable capacity retention and ultra-long lifetime(61.8%over 6650 cycles at 5 A g^(-1))and enhanced rate capability(169 mA h g^(-1)at 5 A g^(-1)).The work may promote the design and deep understanding of electrolyte additives with high molecular polarity for high-performance AZMBs.
Aqueous zinc-ion batteries(AZIBs)are regarded as one of the most promising rivals in the upcoming high-energy secondary battery market because of their safety and non-toxicity.However,the zinc dendrites growth and hydrogen evolution corrosion of the Zn anode have seriously restricted the application of AZIBs.Herein,to overcome these constraints,a three-dimensional(3D)porous PFA-COOH-CNT artificial solid electrolyte interface(SEl)film with high hydrophobic and zincophilic properties was constructed on Zn anode surface by in-situ polymerization of furfuryl alcohol(FA)and carboxyl carbon nanotubes(COOH-CNT).A series of in-situ,ex-situ characterizations as well as the density functional theory(DFT)calculations reveal that the formed PFA-COOH-CNT SEI film with an abundant oxygen-containing group can provide abundant zincophilic sites and induce homogeneous deposition of Zn^(2+),as well as the hydrophobic alkyl and carbon skeleton in PFA-COOH-CNT SEI film can isolate the direct contact of H_(2)O with Zn anode,and inhibit the occurrence of hydrogen evolution reaction(HER).Accordingly,the Zn anode with PFA-COOH-CNT layer can attain an ultra-long cycle life of 2200 h at 1 mA·cm^(-2),1 mAh·cm^(-2).Simultaneously,the assembled PFA-COOH-CNT@ZnllV2Os full cell can also achieve a high reversible capacity of up to 150.2 mAh•g^(-1) at 1 A·g^(-1) after 400 cycles,with a high average coulombic efficiency(CE)of 98.8%.The designed PFA-COOH-CNT artificial SEI film provides a broad prospect for highly stable zinc anode,and can also be extended to other energy storage systems based on metal anodes.
Silicon is believed to be a critical anode material for approaching the roadmap of lithium-ion batteries due to its high specific capacity. But this aim has been hindered by the quick capacity fading of its electrodes during repeated charge–discharge cycles. In this work, a “soft-hard”double-layer coating has been proposed and carried out on ball-milled silicon particles. It is composed of inside conductive pathway and outside elastic coating, which is achieved by decomposing a conductive graphite layer on the silicon surface and further coating it with a polymer layer.The incorporation of the second elastic coating on the inside carbon coating enables silicon particles strongly interacted with binders, thereby making the electrodes displaying an obviously improved cycling stability. As-obtained double-coated silicon anodes deliver a reversible capacity of 2280 m Ah g^(-1)at the voltage of 0.05–2 V, and maintains over 1763 mAh g^(-1)after 50 cycles. The double-layer coating does not crack after the repeated cycling, critical for the robust performance of the electrodes. In addition, as-obtained silicon particles are mixed with commercial graphite to make actual anodes for lithium-ion batteries. A capacity of 714 mAh g^(-1)has been achieved based on the total mass of the electrodes containing 10 wt.% double-coated silicon particles. Compared with traditional carbon coating or polymeric coating, the double-coating electrodes display a much better performance. Therefore, the double-coating strategy can give inspiration for better design and synthesis of silicon anodes, as well as other battery materials.
Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface,predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution.Particularly,the intricate mechanisms behind the electrochemical discrepancies induced by interfacial Zn^(2+)-solvation and deposition behavior demand comprehensive investigation.Organic molecules endowed with special functional groups (such as hydroxyl,carboxyl,etc.) have the potential to significantly optimize the solvation structure of Zn^(2+)and regulate the interfacial electric double layer (EDL).By increasing nucleation overpotential and decreasing interfacial free energy,these functional groups facilitate a lower critical nucleation radius,thereby forming an asymptotic nucleation model to promote uniform Zn deposition.Herein,this study presents a pioneering approach by introducing trace amounts of n-butanol as solvation regulators to engineer the homogenized Zn (H-Zn) anode with a uniform and dense structure.The interfacial reaction and structure evolution are explored by in/ex-situ experimental techniques,indicating that the H-Zn anode exhibits dendrite-free growth,no by-products,and weak hydrogen evolution,in sharp contrast to the bare Zn.Consequently,the H-Zn anode achieves a remarkable Zn utilization rate of approximately 20% and simultaneously sustains a prolonged cycle life exceeding 500 h.Moreover,the H-Zn//NH_(4)V_(4)O^(10)(NVO) full battery showcases exceptional cycle stability,retaining 95.04%capacity retention after 400 cycles at a large current density of 5 A g^(-1).This study enlightens solvation-regulated additives to develop Zn anode with superior utilization efficiency and extended operational lifespan.
Zinc powder-based anodes encounter significant challenges,including severe side-reactions and nonuniform Zn plating-stripping processes.These issues lead to poor reversibility and low zinc utilization,which substantially impede their practical applications.Herein,we fabricated a multifunctional carbonyl-containing zinc metharcylate(ZMA)layer on the surface of three-dimensional(3D)zinc powder anode through in-situ modification.The ZMA layer with high electronegativity and highly nucleophilic carbonyl group assists the de-solvation process,which is conducive to the Zn^(2+)transport and homogenization of the ionic flux.In addition,the hydrophobic carbon chains in ZMA work as a protective layer to reduce the Zn powder direct contact with free-water and significantly improving side-reactions resistance.Finally,through the synergistic effect of ZMA and 3D Zn structure,the prepared electrode could cycle stably at 20 mA cm^(-2)/20 mAh cm^(-2) for 1153 h(depth of discharge:38.10%).The stable 3D Zn-MnO_(2) battery with a high capacity retention(84.2%over 500 cycles)is also demonstrated.
