A facile finger-paint physical modification for bilateral electrode/electrolyte interface towards a stable aqueous Zn battery

Since the electrode/electrolyte interface(EEI)is the main redox center of electrochemical processes,proper manipulation of the EEI microenvironment is crucial to stabilize interfacial behaviors.Here,a finger-paint method is proposed to enable quick physical modification of glass-fiber separator without complicated chemical technology to modulate EEI of bilateral electrodes for aqueous zinc-ion batteries(ZIBs).An elaborate biochar derived from Aspergillus Niger is exploited as the modification agent of EEI,in which the multi-functional groups assist to accelerate Zn^(2+)desolvation and create a hydrophobic environment to homogenize the deposition behavior of Zn anode.Importantly,the finger-paint interface on separator can effectively protect cathodes from abnormal capacity fluctuation and/or rapid attenuation induced by H_(2)O molecular on the interface,which is demonstrated in modified MnO_(2),V_(2)O_(5),and KMn HCF-based cells.The as-proposed finger-paint method opens a new idea of bilateral interface engineering to facilitate the access to the practical application of the stable zinc electrochemistry.

Thioacetamide Additive Homogenizing Zn Deposition Revealed by In Situ Digital Holography for Advanced Zn Ion Batteries

Zinc ion batteries are considered as potential energy storage devices due to their advantages of low-cost,high-safety,and high theoretical capacity.However,dendrite growth and chemical corrosion occurring on Zn anode limit their commercialization.These problems can be tackled through the optimization of the electrolyte.However,the screening of electrolyte additives using normal electrochemical methods is time-consuming and labor-intensive.Herein,a fast and simple method based on the digital holography is developed.It can realize the in situ monitoring of electrode/electrolyte interface and provide direct information concerning ion concentration evolution of the diffusion layer.It is effective and time-saving in estimating the homogeneity of the deposition layer and predicting the tendency of dendrite growth,thus able to value the applicability of electrolyte additives.The feasibility of this method is further validated by the forecast and evaluation of thioacetamide additive.Based on systematic characterization,it is proved that the introduction of thioacetamide can not only regulate the interficial ion flux to induce dendrite-free Zn deposition,but also construct adsorption molecule layers to inhibit side reactions of Zn anode.Being easy to operate,capable of in situ observation,and able to endure harsh conditions,digital holography method will be a promising approach for the interfacial investigation of other battery systems.

A Review on Engineering Design for Enhancing Interfacial Contact in Solid-State Lithium–Sulfur Batteries

The utilization of solid-state electrolytes(SSEs)presents a promising solution to the issues of safety concern and shuttle effect in Li–S batteries,which has garnered significant interest recently.However,the high interfacial impedances existing between the SSEs and the electrodes(both lithium anodes and sulfur cathodes)hinder the charge transfer and intensify the uneven deposition of lithium,which ultimately result in insufficient capacity utilization and poor cycling stability.Hence,the reduction of interfacial resistance between SSEs and electrodes is of paramount importance in the pursuit of efficacious solid-state batteries.In this review,we focus on the experimental strategies employed to enhance the interfacial contact between SSEs and electrodes,and summarize recent progresses of their applications in solidstate Li–S batteries.Moreover,the challenges and perspectives of rational interfacial design in practical solid-state Li–S batteries are outlined as well.We expect that this review will provide new insights into the further technique development and practical applications of solid-state lithium batteries.

Progress on direct assembly approach for in situ fabrication of electrodes of reversible solid oxide cells

Reversible solid oxide cells(SOCs)are very efficient and clean for storage and regeneration of renewable electrical energy by switching between electrolysis and fuel cell modes.One of the most critical factors governing the efficiency and durability of SOCs technology is the stability of the interface between oxygen electrode and electrolyte,which is conventionally formed by sintering at a high temperature of~1000–1250℃,and which suffers from delamination problem,particularly for reversibly operated SOCs.On the other hand,our recent studies have shown that the electrode/electrolyte interface can be in situ formed by a direct assembly approach under the electrochemical polarization conditions at 800℃and lower.The direct assembly approach provides opportunities for significantly simplifying the cell fabrication procedures without the doped ceria barrier layer,enabling the utilization of a variety of high-performance oxygen electrode materials on barrier layer–free yttria-stabilized zirconia(YSZ)electrolyte.Most importantly,the in situ polarization induced interface shows a promising potential as highly active and durable interface for reversible SOCs.The objective of this progress report is to take an overview of the origin and research progress of in situ fabrication of oxygen electrodes based on the direct assembly approach.The prospect of direct assembly approach in the development of effective SOCs and in the fundamental studies of electrode/electrolyte interface reactions is discussed.

Perspective on powder technology for all-solid-state batteries:How to pair sulfide electrolyte with high-voltage cathode

Sulfide solid electrolytes(SEs)have attracted ever-increasing attention due to their superior roomtemperature ionic conductivity(~10^(-2) S cm^(-1)).Additionally,the integration of sulfide SEs and highvoltage cathodes is promising to achieve higher energy density.However,the incompatible interfaces between sulfide SEs and high-voltage cathodes have been one of the key factors limiting their applications.Therefore,this review presents a critical summarization of the interfacial issues in all-solid-state lithium batteries based on sulfide SEs and high-voltage cathodes and proposes strategies to stabilize the electrolyte/cathode interfaces.Moreover,the future research direction of electrolyte/cathode interfaces and application prospects of powder technology in sulfide-based ASSLBs were also discussed.

NASICONs-type solid-state electrolytes:The history,physicochemical properties,and challenges

Solid-state electrolytes are critical for the development of next-generation high-energy and high-safety rechargeable batteries.Among all the candidates,sodium(Na)superionic conductors(NASICONs)are highly promising because of their evident advantages in high ionic conductivity and high chemical/electrochemical stability.The concept of NASICONs was proposed by Hong and Goodenough et al.in 1976 by reporting the synthesis and characterization of Na1+xZr2(SixP3−x)O12(0≤x≤3),which has attracted tremendous attention on the NASICONs-type solid-state electrolytes.In this review,we are committed to describing the development history of NASICONs-type solid-state electrolytes and elucidating the contribution of Goodenough as a tribute to him.We summarize the correlations and differences between lithium-based and sodium-based NASICONs electrolytes,such as their preparation methods,structures,ionic conductivities,and the mechanisms of ion transportation.Critical challenges of NASICONs-structured electrolytes are discussed,and several research directions are proposed to tackle the obstacles toward practical applications.

Constructing a uniform lithium iodide layer for stabilizing lithium metal anode

The metallic lithium(Li)is the ultimate option in the development of anodes for high-energy secondary batteries.Unfortunately,inferior cycling reversibility and Li dendrites growth of Li metal as anode enormously impede its commercialization.Here,a uniform Li I protective layer is constructed on Li metal anode via a facile and direct solid-gas reaction of Li metal with iodine vapor.The pre-constructed Li I layer possesses more steadily and faster Li ion transport than the conventional SEI layer and contributes to a steady interface for the Li metal anode,which affords a smooth Li deposition morphology without Li dendrites formation.The symmetrical cell with the Li metal anode protected by Li I layer exhibits a longer cycling lifetime of over 700 h at a current density of 1 m A cm^(-2) with Li plating capacity of 1 m Ah cm^(-2).Moreover,the Li I layer protected Li metal anode can still remain high capacity retention of 74.6%after 500 cycles in the full cell paired with NCM523 cathode.The work proposes an easy and effective method to fabricate a uniform and stable protective layer on the Li metal anode and offers a practicable thinking for the commercial implementation of Li metal batteries.

Curvature effects on electric-double-layer capacitance

Understanding the microscopic structure and thermodynamic properties of electrode/electrolyte interfaces is central to the rational design of electric-double-layer capacitors(EDLCs).Whereas practical applications often entail electrodes with complicated pore structures,theoretical studies are mostly restricted to EDLCs of simple geometry such as planar or slit pores ignoring the curvature effects of the electrode surface.Significant gaps exist regarding the EDLC performance and the interfacial structure.Herein the classical density functional theory(CDFT)is used to study the capacitance and interfacial behavior of spherical electric double layers within a coarse-grained model.The capacitive performance is associated with electrode curvature,surface potential,and electrolyte concentration and can be correlated with a regression-tree(RT)model.The combination of CDFT with machine-learning methods provides a promising quantitative framework useful for the computational screening of porous electrodes and novel electrolytes.

Unraveling the decomposition mechanism of Li_(2)CO_(3)in the aprotic medium by isotope-labeled differential electrochemical mass spectrometry

Rechargeable lithium-ion batteries(LIBs)represent the highest energy density in the contemporary energy storage community,typically delivering a practical energy density of 150-350 Wh kg-1in the current technique,which can hardly satisfy the evergrowing demand for the portable electronic devices and power tools requiring long service time[1-3].

Halide-based solid electrolytes:The history,progress,and challenges

Lithium metal solid-state batteries(LMSBs)have attracted extensive attention over the past decades,due to their fascinating advantages of safety and potential for high energy density.Solid-state electrolytes(SEs)with fast ionic transport and excellent stability are indispensable components in LMSBs.Heretofore,a series of inorganic SEs have been extensively explored,such as sulfide-and oxide-based electrolytes.Unfortunately,they both have difficulty in achieving a satisfactory balance of conductivity and stability,and oxides suffer from a high impedance of grain boundaries,while sulfides encounter poor stability.Halide-based solid electrolytes are gradually emerging as one of the most promising candidates for LMSBs due to their advantages of decent room temperature ionic conductivity(>10^(−3)S cm^(−1)),good compatibility with oxide cathode materials,good chemical stability,and scalability.Herein,research and development of the widely studied metal halide SEs including fluorides,chlorides,bromides,and iodides are reviewed,mainly focusing on the structures and ionic conductivities as well as preparation methods and electrochemical/chemical stabilities.And then,based on typical metal halide solid electrolytes,we emphasize the interface issues(grain boundaries,cathode−electrolyte and electrolyte–anode interfaces)that exist in the corresponding LMSBs and summarize the related work on understanding and engineering these interfaces.Furthermore,the typical(or in situ)characterization tools widely used for solid-state interfaces are reviewed.Finally,a perspective on the future direction for developing high-performance LMSBs based on the halide electrolyte family is put out.

Degradation of solid oxide electrolysis cells: Phenomena,mechanisms, and emerging mitigation strategies——A review

Solid oxide electrolysis cell(SOEC) is a promising electrochemical device with high efficiency for energy storage and conversion.However,the degradation of SOEC is a significant barrier to commercial viability.In this review paper,the typical degradation phenomena of SOEC are summarized,with great attention into the anodes/oxygen electrodes,including the commonly used and newly developed anode materials.Meanwhile,mechanistic investigations on the electrode/electrolyte interfaces are provided to unveil how the intrinsic factor,oxygen partial pressure pO2,and the electrochemical operation conditions,affect the interracial stability of SOEC.At last,this paper also presents some emerging mitigation strategies to circumvent long-term degradation,which include novel infiltration method,development of new anode materials and engineering of the microstructure.