Sb-Cu alloy cathode with a novel lithiation mechanism of ternary intermetallic formation: Enabling high energy density and superior rate capability of liquid metal battery

Antimony(Sb) is an attractive cathode for liquid metal batteries(LMBs) because of its high theoretical voltage and low cost.The main obstacles associated with the Sb-based cathodes are unsatisfactory energy density and poor rate-capability.Herein,we propose a novel Sb_(64)Cu_(36)cathode that effectively tackles these issues.The Sb_(64)Cu_(36)(melting point:525℃) cathode presents a novel lithiation mechanism involving sequentially the generation of Li_(2)CuSb,the formation of Li_(3)Sb,and the conversion reaction of Li_(2)CuSb to Li_(3)Sb and Cu.The generated intermetallic compounds show a unique microstructure of the upper floated Li_(2)CuSb layer and the below cross-linked structure with interpenetrated Li_(2)CuSb and Li_(3)Sb phases.Compared with Li_(3)Sb,the lower Li migration energy barrier(0.188 eV) of Li_(2)CuSb significantly facilitates the lithium diffusion across the intermediate compounds and accelerates the reaction kinetics.Consequently,the Li‖Sb_(64)Cu_(36)cell delivers a more excellent electrochemical performance(energy density:353 W h kg^(-1)at 0.4 A cm^(-2);rate capability:0.59 V at 2.0 A cm^(-2)),and a much lower energy storage cost of only 38.45 $ kW h^(-1)than other previously reported Sb-based LMBs.This work provides a novel cathode design concept for the development of high-performance LMBs in applications for large-scale energy storage.

Anode reaction mechanisms of Na|NaCl-CaCl2|Zn liquid metal battery

Na|NaCl-CaCl_(2)|Zn liquid metal battery is regarded as a promising energy storage system for power grids.Despite intensive attempts to present a real mechanism of metal electrodes reaction, those for Na||Zn LMBs are not clear yet. Herein, the anode reactions for the multiple discharge potential plateaus were deduced by means of FactSage thermochemical software, which were subsequently validated by X-ray diffraction analysis and the modeling of phase transformation in the cooling process. A pre-treatment process was proposed for the analysis of anode product composition using the atomic absorption spectrometry method, and the anode states at working temperature(560 ℃) were obtained by the Na-CaZn ternary phase for the first time. The results indicate the discharge of Na and Ca led to the formation of Ca-Zn intermetallic compounds, whilst the extraction of Ca in Ca-Zn intermetallic compounds was responsible for the multiple discharge plateaus. Moreover, it was found that the charging product was in electrochemical double liquid metal layers, which are composed of Na and Ca with dissolved Zn respectively.

Self-discharge mitigation in a liquid metal displacement battery

Recently,a disruptive idea was reported about the discovery of a new type of battery named Liquid Displacement Battery(LDB)comprising liquid metal electrodes and molten salt electrolyte.This cell featured a novel concept of a porous electronically conductive faradaic membrane instead of the traditional ion-selective ceramic membrane.LDBs are attractive for stationary storage applications but need mitigation against self-discharge.In the instant battery chemistry,Li|LiCl-PbCl_(2)|Pb,reducing the diffusion coefficient of lead ions can be a way forward and a solution can be the addition of Pb O to the electrolyte.The latter acts as a supplementary barrier and complements the function of the faradaic membrane.The remedial actions improved the cell’s coulombic efficiency from 92%to 97%without affecting the voltage efficiency.In addition,the limiting current density of a 500 m Ah cell increased from 575 to 831 m A cm;and the limiting power from 2.53 to 3.66 W.Finally,the effect of Pb O on the impedance and polarization of the cell was also studied.

Research on Thermal Management Control Strategy of Electric Vehicle Liquid Cooling Battery Pack

Due to the risk of thermal runaway in the charging and discharging process of a soft packed lithium battery pack for electric vehicles,a stamping channel liquid cooling plate cooling system is designed,and then the heat dissipation problem of the battery pack is solved through reasonable thermal management control strategy.Using computational fluid dynamics simulation software star-CCM+,the thermal management control strategy is optimized through simulation technology,and the temperature field distribution of battery pack is obtained.Finally,an experimental platform is built,combined with experiments,the effectiveness of the thermal management control strategy of the cooling system is verified.The results show that when the battery pack is in the environment of 25℃,the maximum temperature of the cooling system can be lower than 40℃,the maximum temperature difference between all single batteries is within 5℃,and the maximum temperature difference between inlet and outlet coolant is 3℃,which can meet the heat dissipation requirements of the battery pack and prevent out of control heat generation.

Ionic liquid-assisted hydrothermal synthesis of SnS nanoparticles:Electrode materials for lithium batteries,photoluminescence and photocatalytic activities

Tin mono-sulphide（Sn S） nanoparticles（Nps） have been successfully synthesised through ionic liquid assisted hydrothermal method using hydrated tin（II） chloride as a precursor, thiourea as sulphur source precursors using 2-Methoxy ethyl methyl imidazolium methane sulfonate ionic liquid as co-solvent. The Reitveld refinement on powder X-ray diffraction（PXRD） confirmed the presence of orthorhombic Sn S structure as major phase along with traces amount of Sn S2 and Sn2 S3. Diffuse reflectance spectrum studies revealed the energy band gap around 1.38 e V. TEM images confirmed the Sn S Nps with average particle size of 40 nm and HRTEM suggest good crystallinity. The electrochemical property for lithium storage behaviour shows an initial discharge capacity of 658 m Ah/g and it retains discharge capacity of 426 m Ah/g for 16 cycles, at current density 100 m A/g. The obtained results indicate that Sn S Nps to be one of the possible promising anode materials for next generation Lithium batteries. Photoluminescence study of Sn S Nps shows a strong green emission at 530 nm. Sn S Nps were also tested for the photocatalytic adsorption of methylene blue and Rhodamine B.

Construction of ultra-stable NiFe armored catalyst for liquid and flexible quasi-solid-state rechargeable Zn-air batteries

The commercial application of non-precious metal-based electrocatalysts is not only limited by the intrinsic activity of the catalysts,but also the stability of the catalysts is extremely important.Herein,we fabricated an ultra-stable NiFe armored catalyst(Ar-NiFe/NC)by a simple secondary pyrolysis strategy.The as-obtained Ar-NiFe/NC electrocatalyst exhibits an excellent bifunctional oxygen electrocatalytic performance with an activity indicatorΔE of 0.74 V vs.reversible hydrogen electrode(RHE).More importantly,the Ar-NiFe/NC electrocatalyst also shows a remarkable operational and storage stability.After accelerated durability test(ADT)cycles,no obvious degradation of oxygen electrocatalytic performance could be observed.In addition,the Ar-NiFe/NC electrocatalyst still exhibits an unbated oxygen electrocatalytic performance comparable to fresh catalysts after three months of air-exposed storage.The assembled liquid and flexible quasi-solid-state rechargeable Zn-air batteries with the Ar-NiFe/NC electrocatalyst exhibit impressive performance.The liquid rechargeable Zn-air batteries possess a high open-circuit voltage(OCV)of 1.43 V and a salient peak power density of 146.40 mW·cm^(−2),while the flexible quasi-solid-state rechargeable Zn-air batteries also exhibit an excellent OCV of 1.60 V and an exciting peak power density of 41.99 mW·cm^(−2).

Fundamentals,preparation,and mechanism understanding of Li/Na/Mg-Sn alloy anodes for liquid and solid-state lithium batteries and beyond

Lithium metal is one of the most promising anodes to develop high energy density and safe energy storage devices due to its highest theoretical capacity(3860 mAh·g^(−1))and lowest electrochemical potential,demonstrating great potential to fulfill unprecedented demand from electronic gadgets,electric vehicles,and grid storage.Despite these good merits,lithium metal suffers from low Coulombic efficiency and dendritic growth,leading to internal short-circuiting of the cell and raising safety concerns about employing lithium metal as an anode.Recently,lithium-tin(Li-Sn)alloys,among other lithium alloys,have emerged as a potential alternative to lithium metal to efficiently suppress the lithium dendrite formation and reduce interfacial resistance for safer and longer-lasting lithium batteries.Accordingly,this work first reviews the fundamentals of Li-Sn alloys,and critically analyzes the failure mechanisms of pristine Li-metal anode and how Li-Sn alloys could overcome those challenges.The subsequent section examines various strategies to synthesize Li-Sn bulk and protection film alloys,followed by an evaluation of symmetric cell performance.Furthermore,the comparative electrochemical performance of full cells against different cathodes and solid electrolytes provides an overview of the present research.Subsequently,advanced characterization techniques were discussed to visualize lithium dendrites directly and quantify the mechanical performance of Li-Sn alloys.Last but not the least,the state-of-the-art progress of applying M-Sn(M=Na and Mg)beyond lithium batteries was summarized.In closing,this work identifies the critical challenges and provides future perspectives on Li-Sn alloy for lithium batteries and beyond.

Inhomogeneous lithium-storage reaction triggering the inefficiency of all-solid-state batteries

All-solid-state batteries offer an attractive option for developing safe lithium-ion batteries.Among the various solid-state electrolyte candidates for their applications,sulfide solid electrolytes are the most suitable owing to their high ionic conductivity and facile processability.However,their performance is extensively lower compared with those of conventional liquid electrolyte-based batteries mainly because of interfacial reactions between the solid electrolytes and high capacity cathodes.Moreover,the kinetic evolution reaction in the composite cathode of all-solid-state lithium batteries has not been actively discussed.Here,electrochemical analyses were performed to investigate the differences between the organic liquid electrolyte-based battery and all-solid-state battery systems.Combined with electrochemical analyses and synchrotron-based in situ and ex situ X-ray analyses,it was confirmed that inhomogeneous reactions were due to physical contact.Loosely contacted and/or isolated active material particles account for the inhomogeneously charged regions,which further intensify the inhomogeneous reactions during extended cycles,thereby increasing the polarization of the system.This study highlighted the benefits of electrochemo-mechanical integrity for securing a smooth conduction pathway and the development of a reliable homogeneous reaction system for the success of solid-state batteries.

Advancing knowledge of plasma spraying coatings for Li||Sb-Sn liquid metal batteries by X-ray micro-CT

The performance of Li||Sb-Sn liquid metal batteries(LMBs) is hindered by the corrosion of the Sb-Sn cathode on its current collector. Herein, a uniform, dense, and low-oxidized W coating was prepared by plasma spraying, which can effectively resist the corrosion of the cathode and improve the cycle stability of the Li||Sb-Sn LMBs. For the first time, micro-CT nondestructive inspection is applied in the field of LMBs. The corrosion micromorphology and composition evolution of the SS304 matrix and Sb-Sn cathode with or without the plasma-sprayed W coating is obtained without disassembling the battery, which proves that the W coating can effectively protect the SS304 matrix. Our autonomous new LMB device for nondestructive inspection is universal and can be applied to different LMBs systems for advancing knowledge of corrosion mechanism and protection. This work guarantees the ability to directly visualize the inner critical positions in three dimensions and fills the knowledge gap in the field of LMB detection technology.