Selective leaching of lithium from spent lithium-ion batteries using sulfuric acid and oxalic acid

Traditional hydrometallurgical methods for recovering spent lithium-ion batteries(LIBs)involve acid leaching to simultaneously extract all valuable metals into the leachate.These methods usually are followed by a series of separation steps such as precipitation,extraction,and stripping to separate the individual valuable metals.In this study,we present a process for selectively leaching lithium through the synergistic effect of sulfuric and oxalic acids.Under optimal leaching conditions(leaching time of 1.5 h,leaching temperature of 70°C,liquid-solid ratio of 4 mL/g,oxalic acid ratio of 1.3,and sulfuric acid ratio of 1.3),the lithium leaching efficiency reached89.6%,and the leaching efficiencies of Ni,Co,and Mn were 12.8%,6.5%,and 21.7%.X-ray diffraction(XRD)and inductively coupled plasma optical emission spectrometer(ICP-OES)analyses showed that most of the Ni,Co,and Mn in the raw material remained as solid residue oxides and oxalates.This study offers a new approach to enriching the relevant theory for selectively recovering lithium from spent LIBs.

Recovery of Li, Ni, Co and Mn from spent lithium-ion batteries assisted by organic acids: Process optimization and leaching mechanism

The proper recycling of spent lithium-ion batteries(LIBs)can promote the recovery and utilization of valuable resources,while also negative environmental effects resulting from the presence of toxic and hazardous substances.In this study,a new environmentally friendly hydro-metallurgical process was proposed for leaching lithium(Li),nickel(Ni),cobalt(Co),and manganese(Mn)from spent LIBs using sulfuric acid with citric acid as a reductant.The effects of the concentration of sulfuric acid,the leaching temperature,the leaching time,the solid-liquid ratio,and the reducing agent dosage on the leaching behavior of the above elements were investigated.Key parameters were optimized using response surface methodology(RSM)to maximize the recovery of metals from spent LIBs.The maxim-um recovery efficiencies of Li,Ni,Co,and Mn can reach 99.08%,98.76%,98.33%,and 97.63%.under the optimized conditions(the sulfuric acid concentration was 1.16 mol/L,the citric acid dosage was 15wt%,the solid-liquid ratio was 40 g/L,and the temperature was 83℃ for 120 min),respectively.It was found that in the collaborative leaching process of sulfuric acid and citric acid,the citric acid initially provided strong reducing CO_(2)^(-),and the transition metal ions in the high state underwent a reduction reaction to produce transition metal ions in the low state.Additionally,citric acid can also act as a proton donor and chelate with lower-priced transition metal ions,thus speeding up the dissolution process.

Cooperative composites anchored with single atom Pb and carbon confined PbO nanoparticles for superior lead-carbon batteries

The mitigation of sulphation and parasitic hydrogen evolution is considered as prominent research emphasis for the development of lead-carbon batteries(LCBs)in large-scale energy storage applications.Here,cooperative Pb-C composites consisting of single atom Pb and carbon-encapsulated PbO nanoparticles were prepared by freeze-drying technique and pyrolytic reduction to address above obstacles.The innovative use of Pb^(2+)to cross-link sodium alginate enabled a uniform distribution of Pb in the composites,generating Pb-C-PbO three-phase heterostructure.Experimental analysis and theoretical calculations revealed the synergistic interactions between single-atom Pb and PbO nanoparticles in suppressing parasitic hydrogen evolution and promoting the adsorption of Pb atoms.The presence of monatomic Pb and PbO enhanced the affinity of the composites for the negative active materials and facilitated the transformation of the active materials from bulk into spherical shapes to enhance the specific surface area,thereby counteracting sulphation.Through the coordinated integration of various functionalities offered by Pb@C-x,the cycle life of the battery at HRPSoC reaches 7025 cycles,which is two times for LCB with pure carbon materials.Additionally,the discharge capacity increased from 3.52 to 3.79 Ah.This study provides substantial insights into the construction of Pb-C composites for LCBs to inhibit negative sulphation and hydrogen evolution.

Boric Acid-Assisted Pyrolysis for High-Loading Single-Atom Catalysts to Boost Oxygen Reduction Reaction in Zn-Air Batteries

The emerging of single-atom catalysts(SACs)offers a great opportunity for the development of advanced energy storage and conversion devices due to their excellent activity and durability,but the actual mass production of high-loading SACs is still challenging.Herein,a facile and green boron acid(H_(3)BO_(3))-assisted pyrolysis strategy is put forward to synthesize SACs by only using chitosan,cobalt salt and H_(3)BO_(3)as precursor,and the effect of H_(3)BO_(3)is deeply investigated.The results show that molten boron oxide derived from H_(3)BO_(3)as ideal high-temperature carbonization media and blocking media play important role in the synthesis process.As a result,the acquired Co/N/B tri-doped porous carbon framework(Co-N-B-C)not only presents hierarchical porous structure,large specific surface area and abundant carbon edges but also possesses high-loading single Co atom(4.2 wt.%),thus giving rise to outstanding oxygen catalytic performance.When employed as a catalyst for air cathode in Zn-air batteries,the resultant Co-N-B-C catalyst shows remarkable power density and long-term stability.Clearly,our work gains deep insight into the role of H_(3)BO_(3)and provides a new avenue to synthesis of high-performance SACs.

Selection of Negative Charged Acidic Polar Additives to Regulate Electric Double Layer for Stable Zinc Ion Battery

Zinc-ion batteries are promising for large-scale electrochemical energy storage systems,which still suffer from interfacial issues,e.g.,hydrogen evolution side reaction(HER),self-corrosion,and uncontrollable dendritic Zn electrodeposition.Although the regulation of electric double layer(EDL)has been verified for interfacial issues,the principle to select the additive as the regulator is still misted.Here,several typical amino acids with different characteristics were examined to reveal the interfacial behaviors in regulated EDL on the Zn anode.Negative charged acidic polarity(NCAP)has been unveiled as the guideline for selecting additive to reconstruct EDL with an inner zincophilic H_(2)O-poor layer and to replace H_(2)O molecules of hydrated Zn^(2+)with NCAP glutamate.Taking the synergistic effects of EDL regulation,the uncontrollable interface is significantly stabilized from the suppressed HER and anti-self-corrosion with uniform electrodeposition.Consequently,by adding NCAP glutamate,a high average Coulombic efficiency of 99.83%of Zn metal is achieved in Zn|Cu asymmetrical cell for over 2000 cycles,and NH4V4O10|Zn full cell exhibits a high-capacity retention of 82.1%after 3000 cycles at 2 A g^(-1).Recapitulating,the NCAP principle posted here can quicken the design of trailblazing electrolyte additives for aqueous Zn-based electrochemical energy storage systems.

Reductive smelting of spent lead–acid battery colloid sludge in a molten Na_2CO_3 salt

Lead extraction from spent lead–acid battery paste in a molten Na2CO3 salt containing Zn O as a sulfur-fixing agent was studied. Some influencing factors, including smelting temperature, reaction time, Zn O and salt dosages, were investigated in detail using single-factor experiments. The optimum conditions were determined as follows: T = 880°C; t = 60 min; Na2CO3/paste mass ratio = 2.8:1; and the Zn O dosage is equal to the stoichiometric requirement. Under the optimum conditions, the direct recovery rate of lead reached 98.14%. The results suggested that increases in temperature and salt dosage improved the direct recovery rate of lead. XRD results and thermodynamic calculations indicated that the reaction approaches of lead and sulfur were Pb SO4→Pb and Pb SO4→Zn S, respectively. Sulfur was fixed in the form of Zn S, whereas the molten salt did not react with other components, serving only as a reaction medium.

A low-cost green approach for synthesis of lead oxide from waste lead ash for use in new lead-acid batteries

This paper proposes a novel method relating to the recycling of waste lead ash originated from procedure of lead alloy production.The spent lead ash was first disposed by acetic acid leaching system,where lead ash structure wrapping impurities would be destroyed.The synthesis of lead oxide products was conducted at a lower temperature of 90℃.The effect of molar ratio of CH3 COOH to lead content of the ash on leaching efficiency was studied through the acetic acid leaching system.The results demonstrate that 84.6%of lead could be obtained in the leaching solution,while merely 0.7%of Fe blend in solution within a leaching time of 120 min.In the stage of lead oxide synthesis from leaching solution,the yield of lead oxide products could reach up to 94.4%when the molar ratio of NaOH to lead in filtrate was 2.5.This novel green method could shed light on the reuse of lead from exhausted ash with a much more convenient and environmentally friendly procedure.

Addition of Ce as additive to Pb-Ca-Sn-Al grid alloy for lead acid battery

The study on three Pb Ca Sn Al alloys with 0.08%, 0.4% and 1.0% of Ce indicates that the addition of Ce results in an obvious increase in the tensile strength and hardness of the alloys, an increase in the overpotentials of hydrogen and oxygen evolution and the corrosion resistance as well. The study on the corrosion film formed on the alloys by cyclic voltammetry shows that the addition of Ce slows down the formation of corrosion film. It is therefore concluded from the experimental results that the addition of Ce can increase the tensile strength and HB of Pb Ca alloy and the tensile strength and HB of the alloy increase with the increase of Ce; the addition of Ce also increases the hydrogen and oxygen evolution overpotentials of Pb Ca alloy, and when the content of Ce is 1.0%, the alloy has the highest hydrogen and oxygen evolution overpoteatials; the addition of Ce improves the anticorrosion capability of the alloy, and when the content Ce is 1.0%, the alloy has the best anticorrosion capability; and the addition of Ce also slows down the formation of corrosion film.

Graphene oxide/hydrotalcite modified polyethersulfone nanohybrid membrane for the treatment of lead ion from battery industrial effluent

In the present study, polyethersulfone based nanohybrid membranes were effectively fabricated by incorporating graphene oxide(GO) and hydrotalcite(HT) nanosheets into the membrane structure. HT was prepared to overcome the irreversible agglomeration behavior of GO at a high concentration which affects the performance of the membranes. In particular, the shedding of HT in formamide provides a two-dimensional nanosheet with a higher positive charge density to prevent the restacking of GO nanosheets. Here, exfoliated GO and HT with different combinations(1:1, 1:2 and 1:3) were infused in the membrane matrix to treat lead-acid battery effluent effectively. Finally, the hybrid membranes were characterized for hydrophilicity, mechanical strength and pure water flux. In combination with the superior properties of GO and HT, the prepared hybrid membranes can be used as effectively to improve the separation and permeation performance. The phase inversion process eliminated the leaching of nanoparticles from the membrane matrix. The reusability of the hybrid membrane was achieved using0.1 mol·L^(-1)NaOH solution and reused without significant reduction in lead removal efficiency. The cost analysis of the membrane was also estimated from the lab study. Therefore, the present study suggested the selective and sustainable treatment of lead from a real-life effluent.

Effect of lead foam grid on performance of lead-acid battery

In order to increase the specific energy and specific power of a lead-acid battery, lead foam grid was prepared by electrodepositing Pb-Sn alloy on a copper foam substrate and used as negative current collector for a lead acid battery whose capacity was limited by the negative plate. Comparing the effect of the cast grid, under the same conditions, the mass of lead foam grid decreases by 35%, and the area of lead foam contacted with active material increases by about 20 times. Under 2 h rate discharge condition, with a high current （3 0 I2） e and low-temperature （-10 ℃, I2） discharge system, the lead foam grid markedly boosts the discharge performance of lead acid battery. It increases not only the negative electrode mass specific capacity by 27%,37% and 29%,but also the utilization efficiency of the negative active material by 5%. Compared with the negative electrode of cast grid, XRD and SEM results show that after 20 cycles at the state of charge, the sponge lead in the negative lead foam electrode has smaller crystals and less PbSO4 on its surface. Meanwhile, at the state of full discharge, the PbSO4 crystals are smaller and occur less on the surface of lead foam electrode. This indicates its active material reacts more uniformly.

Research on thin grid materials of lead-acid batteries

A detailed investigation on Pb-Ca-Sn alloys was made in order to choose suitable grid alloys materials for thin plate lead-acid batteries. The electrochemical performances of alloys were investigated by electrochemical corrosion experiment, scanning electron microscope (SEM), and cyclic voltammetry (CV) test. The results indicate that Pb-Ca-Sn-Bi-Cu alloys can be used to make the grids used for thin grid lead-acid batteries, the content of bismuth has primary effects on the corrosion resistance of grid alloys, the composition of alloys plays an important role on batteries performance, and appropriate scale of elements can be choosed to obtain optimal electrochemical performance. The lead-acid batteries using this kind of grid show good performance by cycle life test.

Experiments Study on Charge Technology of Lead-Acid Electric Vehicle Batteries

The basic theory of the fast charge and several charge methods are introduced. In order to heighten charge efficiency of valve-regulated lead-acid battery and shorten the charge time, five charge methods are investigated with experiments done on the Digatron BNT 400-050 test bench. Battery current, terminal voltage, capacity, energy and terminal pole temperature during battery experiment were recorded, and corresponding curves were depicted. Battery capacity-time ratio, energy efficiency and energy-temperature ratio are put forward to be the appraising criteria of lead-acid battery on electric vehicle （EV）. According to the appraising criteria and the battery curves, multistage-current/negative-pulse charge method is recommended to charge lead-acid EV battery.

Preparation of lithium-ion battery anode materials from graphitized spent carbon cathode derived from aluminum electrolysis

Graphitized spent carbon cathode(SCC)is a hazardous solid waste generated in the aluminum electrolysis process.In this study,a flotation-acid leaching process is proposed for the purification of graphitized SCC,and the use of the purified SCC as an anode material for lithium-ion batteries is explored.The flotation and acid leaching processes were separately optimized through one-way experiments.The maximum SCC carbon content(93wt%)was achieved at a 90%proportion of−200-mesh flotation particle size,a slurry concentration of 10wt%,a rotation speed of 1600 r/min,and an inflatable capacity of 0.2 m^(3)/h(referred to as FSCC).In the subsequent acid leaching process,the SCC carbon content reached 99.58wt%at a leaching concentration of 5 mol/L,a leaching time of 100 min,a leaching temperature of 85°C,and an HCl/FSCC volume ratio of 5:1.The purified graphitized SCC(referred to as FSCC-CL)was utilized as an anode material,and it exhibited an initial capacity of 348.2 mAh/g at 0.1 C and a reversible capacity of 347.8 mAh/g after 100 cycles.Moreover,compared with commercial graphite,FSCC-CL exhibited better reversibility and cycle stability.Thus,purified SCC is an important candidate for anode material,and the flotation-acid leaching purification method is suitable for the resourceful recycling of SCC.

Omni-functional simultaneous interfacial treatment for enhancing stability and outgassing suppression of lithium-ion batteries

Ni-rich layered oxides in lithium-ion batteries have problems with gas generation and electrochemical performance reduction due to residual lithium's reaction on the surface with the electrolyte.To address this issue,in this study,the Acid solvent evaporation(AsE)method has been proposed as a potential method to remove residual lithium while promoting the formation of a new LiNO_(3)-derived coating layer on the cathode surface.The reduction of residual lithium using the ASE method and the construction of a LiNO_(3)-derived coating layer suppresses gas evolution caused by the side effects of the electrolyte,improves electrochemical performance,and improves thermal stability by facilitating the smooth movement of lithium ions.Furthermore,the structural stability and resistance change due to the LiNO_(3)-derived coating layer effects is guaranteed through cycling and DCIR of the pouch cell.As a result,compared to Pristine,the capacity retention of coin cells increased by 8%after 100 cycles,and pouch cells increased by 25%after 160 cycles.In addition,after cycling the pouch cell,CO_(2) gas has significantly reduced by about 30%compared to Pristine using gas chromatography.The ASE method effectively forms a robust LiNO_(3)-derived coating layer on the cathode active material,which helps minimize electrolyte reactivity,suppress ,CO_(2) emissions,enhance surface structure stability,improve thermal stability,and improveoverallbatteryperformance.

Structure Regulation of Electric Double Layer via Hydrogen Bonding Effect to Realize High-Stability Lithium-Metal Batteries

The interfacial chemistry of solid electrolyte interphases(SEI)on lithium(Li)electrode is directly determined by the structural chemistry of the electric double layer(EDL)at the interface.Herein,a strategy for regulating the structural chemistry of EDL via the introduction of intermolecular hydrogen bonds has been proposed(p-hydroxybenzoic acid(pHA)is selected as proof-of-concept).According to the molecular dynamics(MD)simulation and density functional theory(DFT)calculation results,the existence of hydrogen bonds realizes the anion structural rearrangement in the EDL,reduces the lowest unoccupied molecular orbital(LUMO)energy level of anions in the EDL,and the number of free solvent molecules,which promotes the formation of inorganic species-enriched SEI and eventually achieves the dendrite-free Li deposition.Based on this strategy,Li‖Cu cells can stably run over 185 cycles with an accumulated active Li loss of only 2.27 mAh cm^(-2),and the long-term cycle stability of Li‖Li cells is increased to 1200 h.In addition,the full cell pairing with the commercial LiFePO_(4)(LFP)cathodes exhibits stable cycling performance at 1C,with a capacity retention close to 90%after 200 cycles.

In situ synthesis of SnPS_(3)/Ti_(3)C_(2)T_(x) hybrid anode via molten salt etching method for superior sodium-ion batteries

Recently,SnPS_(3) has gained attention as an impressive sodium-ion battery anode material because of its significant theoretical specific capacity derived from the conversion-alloying reaction mechanism.Nevertheless,its practical applicability is restricted by insufficient rate ability,and severe capacity loss due to inadequate electrical conductivity and dramatic volume expansion.Inspired by the electrochemical enhancement effect of MXene substrates and the innovative Lewis acidic etching for MXene preparation,SnPS_(3)/Ti_(3)C_(2)T_(x) MXene(T=-Cl and-O) is constructed by synchronously phospho-sulfurizing Sn/Ti_(3)C_(2)T_(x) precursor.Benefiting from the boosted Na^(+) diffusion and electron transfer rates,as well as the mitigated stress expansion,the synthesized SnPS_(3/)Ti_(3)C_(2)T_(x) composite demonstrates enhanced rate capability(647 mA h g^(-1) at 10 A g^(-1)) alongside satisfactory long-term cycling stability(capacity retention of 94.6% after 2000 cycles at 5 A g^(-1)).Importantly,the assembled sodium-ion full cell delivers an impressive capacity retention of 97.7% after undergoing 1500 cycles at 2 A g^(-1).Moreover,the sodium storage mechanism of the SnPS_(3/)Ti_(3)C_(2)T_(x) electrode is elucidated through in-situ and ex-situ characterizations.This work proposes a novel approach to ameliorate the energy storage performance of thiophosphites by facile in-situ construction of composites with MXene.

Pb-Ca-Sn-Ba Grid Alloys for Valve-Regulated Lead Acid Batteries

The effect of barium additives on the process of anodic corrosion of lead-tin-calcium alloys in a 4.8 М sulfuric acid solution was studied. Cyclic voltammetry, impedance spectroscopy, weight loss measurements and scanning electronic microscope analysis have allowed exploring the oxidation process and characterizing the formed corrosion layer. According to our results, barium introduction into lead-tin-calcium alloys increases their hardness, reduces their electrochemical activity, and improves their corrosion stability. Reduction of the calcium content in the alloy can be compensated by adding barium. Barium dopation at lead-tin-calcium alloys decreases the resistance of the oxide layer formed on the grid surface, in a deeply discharged state, and raises its resistance during floating conditions and at a charged state of the positive electrode.

Study of the Charge Acceptance of Small-Size Sealed Lead-Acid Batteries

ＳｔｕｄｙｏｆｔｈｅＣｈａｒｇｅＡｃｃｅｐｔａｎｃｅｏｆＳｍａｌｌ－ＳｉｚｅＳｅａｌｅｄＬｅａｄ－ＡｃｉｄＢａｔｔｅｒｉｅｓＤＯＮＧＢａｏｇｕａｎｇ；ＺＨＡＮＧＱｉｕｄａｏ；ＭＵＪｕｎｊｉａｎｇ（董保光，张秋道，穆俊江）（Ｄｅｐｔ．ｏｆＡｐｐｌｉｅｄ...

PREPARATION OF LEAD-ACID BATTERY USING ELECTROPLATED RETICULATED SiC AS THE POSITIVE CURRENT COLLECTOR

The possibility of using Pb-electroplated reticulated SiC as the positive current collector for lead-acid batteries was investigated. Reticulated SiC with two aperture sizes (3 and 2mm) were tested as the substrate of positive electrode. It was found that the reticulated SiC has an excellent corrosion resistance in H2SO4 solution, and the Pb layer electroplated on reticulated SiC showed analogous electrochemical behavior to metal Pb. Preliminary test of the battery performance indicated that the utilization efficiency of the positive active mass of new designed batteries are improved compared with the conventional batteries. The improvement could be ascribed to the high specific surface area of the reticulated structured positive current collector, which was further supported by the even better performance of the battery made from a smaller aperture size (2mm) reticulated SiC as the substrate of the positive electrode.

Self-Discharge in Valve-Regulated Sealed Lead-Acid Batteries

Factors that cause the self-discharge in valve-regulated sealed lead-acid batteries are discussed and measures to inhibit the self-discharge are put forward.