Progress,challenges,and prospects of spent lithium-ion batteries recycling:A review

The recycling and reutilization of spent lithium-ion batteries(LIBs)have become an important measure to alleviate problems like resource scarcity and environmental pollution.Although some progress has been made,battery recycling technology still faces challenges in terms of efficiency,effectiveness and environmental sustainability.This review aims to systematically review and analyze the current status of spent LIB recycling,and conduct a detailed comparison and evaluation of different recycling processes.In addition,this review introduces emerging recycling techniques,including deep eutectic solvents,molten salt roasting,and direct regeneration,with the intent of enhancing recycling efficiency and diminishing environmental repercussions.Furthermore,to increase the added value of recycled materials,this review proposes the concept of upgrading recycled materials into high value-added functional materials,such as catalysts,adsorbents,and graphene.Through life cycle assessment,the paper also explores the economic and environmental impacts of current battery recycling and highlights the importance that future recycling technologies should achieve a balance between recycling efficiency,economics and environmental benefits.Finally,this review outlines the opportunities and challenges of recycling key materials for next-generation batteries,and proposes relevant policy recommendations to promote the green and sustainable development of batteries,circular economy,and ecological civilization.

The mystic role of high-entropy designs in rechargeable metal-ion batteries:A review

Rechargeable metal-ion batteries, such as lithium-ion batteries(LIBs) and sodium-ion batteries(SIBs),have raised more attention because of the large demand for energy storage solutions. Undoubtedly, electrode materials and electrolytes are key parts of batteries, exhibiting critical influence on the reversible capacity and span life of the metal-ion battery. Nonetheless, researchers commonly express concerns regarding the stability of both electrodes and electrolytes. Given its commendable stability attributes,high-entropy materials have garnered widespread acclaim and have been applied in many fields since their inception, notably in energy storage. However, while certain high-entropy designs have achieved substantial breakthroughs, some have failed to meet anticipated outcomes within the high energy density energy storage materials. Moreover, there is a lack of comprehensive summary research on the corresponding mechanisms and design principles of high-entropy designs. This review examines the current high-entropy designs for cathodes, anodes, and electrolytes, aiming to summarize the design principle,potential mechanisms, and electrochemical performance. We focus on their structural characteristics,interface characteristics, and prospective development trends. At last, we provide a fair evaluation along-side succinct development suggestions.

Synthesis and performance of carbon-modified LiFePO_4 using an in situ PVA pyrolysis procedure

LiFePOa/carbon composite cathode material was prepared by granulating and subsequent pyrolysis processing in N2 atmosphere with polyvinyl alcohol （PVA） as the carbon source. The influences of carbon content on the microstructure and battery performance were investigated. Single LiFePO4 phase and amorphous carbon can be found in the products. A special micro-morphology of the optimum sample was observed. The discharge capacity of the cell with the optimum cathode was 135 mAh.g^-1, close to the charge capacity of 153 mAh.g^-1 at 17 mA.g^-1. The influence of ambient temperature on the cell capacity was investigated. The temperature dependence of its electrochemical characteristic was evaluated by using AC impedance spectroscopy. A new equivalent circuit based on the charge and mass transfer control process in an electrode was proposed to fit the obtained AC impedance spectra. The tendency of every element in the equivalent circuit was used to interpret the temperature dependence of the capacity of the optimum cathode.

Porous spherical NiO@NiMoO4@PPy nanoarchitectures as advanced electrochemical pseudocapacitor materials

In this work, a rational design and construction of porous spherical Ni O@NiMoO4 wrapped with PPy was reported for the application of high-performance supercapacitor(SC). The results show that the NiMoO4 modification changes the morphology of Ni O, and the hollow internal morphology combined with porous outer shell of Ni O@NiMoO4 and Ni O@NiMoO4@PPy hybrids shows an increased specific surface area(SSA), and then promotes the transfer of ions and electrons. The shell of NiMoO4 and PPy with high electronic conductivity decreases the charge-transfer reaction resistance of Ni O, and then improves the electrochemical kinetics of Ni O. At 20 Ag^-1, the initial capacitances of Ni O, NiMoO4, Ni O@NiMoO4 and Ni O@NiMoO4@PPy are 456.0, 803.2, 764.4 and 941.6 Fg^-1, respectively. After 10,000 cycles, the corresponding capacitances are 346.8, 510.8, 641.2 and 904.8 Fg^-1, respectively. Especially, the initial capacitance of Ni O@NiMoO4@PPy is 850.2 Fg^-1, and remains 655.2 Fg^-1 with a high retention of 77.1% at30 Ag^-1 even after 30,000 cycles. The calculation result based on density function theory shows that the much stronger Mo-O bonds are crucial for stabilizing the Ni O@NiMoO4 composite, resulting in a good cycling stability of these materials.

Novel P2-type layered medium-entropy ceramics oxide as cathode material for sodium-ion batteries

High-entropy oxides(HEOs)and medium-entropy oxides(MEOs)are new types of single-phase solid solution materials.MEOs have rarely been reported as positive electrode material for sodium-ion batteries(SIBs).In this study,we first proposed the concept of the application of MEOs in SIBs.P2-type 3-cation oxide Na_(2/3)Ni_(1/3)Mn_(1/3)Fe_(1/3)O_(2)(NaNMF)and 4-cation oxide Na_(2/3)Ni_(1/3)Mn_(1/3)Fe_(1/3-x)Al_(x)O_(2)(NaNMFA)were prepared using the solid-state method,rather than the doping technology.In addition,the importance of the concept of entropy stabilization in material performance and battery cycling was demonstrated by testing 3-cation(NaNMF)and 4-cation(NaNMFA)oxides in the same system.Thus,NaNMFA can provide a reversible capacity of about 125.6 mAh-g”1 in the voltage range of 2-4.2 V,and has enhanced cycle stability.The capacity and decay law of the MEO batteries indicate that the configurational entropy(1.28 R(NaNMFA)>1.10 R(NaNMF))of the cationic system,is the main factor affecting the structural and cycle stability of the electrode material.This work emphasizes that the rational design of MEOs with novel structures and different electrochemically active elements may be the strategy for exploring high-performance SIB cathode materials in next-generation energy storage devices.

Precise tuning of low-crystalline Sb@Sb_(2)O_(3) confined in 3D porous carbon network for fast and stable potassium ion storage

Metal antimony(Sb)is a promising anode material of potassium-ion batteries(PIBs)for its high theoretical capacity but limited by its inferior cycle stability due to the serious volume expansion during cycling.Herein,we design and construct a kind of low-crystalline Sb nanoparticles coated with amorphous Sb2O3 and dispersed into three-dimensional porous carbon via a strategy involving NaCl template-assisted insitu pyrolysis and subsequent low-temperature heat-treated in air.Significantly,the crystallinity and ratio of Sb/Sb_(2)O_(3) have been precisely tuned and controlled,and the optimized sample of HTSb@Sb_(2)O_(3)@C-4 displays a high reversible specific capacity of 543.9 m Ah g^(-1) at 0.1 A g^(-1),superior rate capability and excellent cycle stability(~273 m Ah g^(-1) at 2 A g^(-1) after 2000 cycles)as an anode of PIBs.The outstanding potassium-ion storage performance can be ascribed to the appropriate crystallinity and the multiplebuffer-matrix structure comprising an interconnected porous conductive carbon to relieve the volume changes and suppress the aggregation of Sb,a Sb nanoparticle core to shorten the ion transport pathways and decrease the mechanical stress,and a low-crystalline Sb_(2)O_(3) as the shell to consolidate the interface between Sb and carbon as well as facilitate the rapid electron transport.The dynamic analysis shows that the composite is mainly controlled by pseudocapacitance mechanism.This work provides a novel thought to design high-performance composite electrode in energy storage devices.

Improving the cycling stability and rate capability of LiMn_(0.5)Fe_(0.5)PO_(4)/C nanorod as cathode materials by LiAlO_(2) modification

LiMn_(0.5)Fe_(0.5)PO_(4)(LMFP)@C and LMFP@LiAlO_(2)@C nanorods are successfully synthesized by a solvothermal process followed by a calcination at H2/Ar atmosphere.The carbon coating and LiAlO_(2) coating does not change the morphology and particle size of LMFP,and all samples show nanorod morphology with 50-100 nm in width and 200-300 nm in length.The results show that LiAlO_(2) coating can offer rapid charge transfer channels with improved intercalation/de-intercalation kinetics of Li ions,which make an outstanding rate capability and cycling stability of as-synthesized LMFP@LiAlO_(2)@C cathodes.As a result,LiAlO_(2) coating effectively improves the rate capability and cycling stability of LMFP cathode even at high discharge rates.Hence,LMFP@LiAlO_(2)(5 wt%)@C indicates an outstanding rate performance with a reversible discharge capacity of 137.6 and 113.2 mAh g^(-1) discharged at 0.05 C and 5 C rates,and the composite also shows a good cycle performance with an excellent capacity of 107 mAh g^(-1) and 86.4% capacity retention rate at 5 C rate after 100 cycles.Therefore,the LiAlO_(2) coating can be considered as an effective way to improve the electrochemical properties of LMFP.

Research progress of tunnel-type sodium manganese oxide cathodes for SIBs

Among the large energy storage batteries,the sodium ion batteries(SIBs)are attracted huge interest due to the fact of its abundant raw materials and low cost,and has become the most promising secondary battery.Tunnel-type sodium manganese oxides(TMOs)are industrialized cathode materials because of their simple synthesis method and proficient electrochemical performance.Na_(0.44)MnO_(2)(NMO)is considered the best candidate material for all tunnel-type structural materials.In this paper,the research progress in charge and discharge of cathode materials for tunnel-type structural SIBs is reviewed,the redox mechanism and all sorts of synthesis methods and different coating methods lead to different morphology and electrochemical properties of materials and the classification of electrolytes and nonaqueous electrolytes.The development and utility of aqueous solutions are discussed,and the mechanism is analyzed.Summarized the cationic potential of the transition metal oxide for tunnel structure,plays a vital role in predicting and designing the cathode material of this structure.In addition,the future opportunities and challenges for such tunnel-type SIBs in this field are described in detail.

Excess capacity on compound phases of Li_(2)FeTiO_(4) composite cathode materials synthesized by hydrothermal reaction using optional titanium sources to boost battery performance

Li_(2)FeTiO_(4) composites have been produced using commercial LiAC,FeCl_(2) and different titanium sources by hydrothermal synthesis(HS)at 175℃and subsequent annealing at 700℃.Impure phase TiO_(2),Fe_(2)O_(3) and FeTi0_(4) were detected out among the Li_(2)FeTiO_(4) composites with different titanium sources.Micron and nano-sized particles of Li2FeTiO4 were prepared from various titanium raw materials,with nano-sized particles predominating when titanium raw materials were layered hydrogen titanate nanowire(H2Ti3O7 NW,HTO-NW)and titanium oxide nanotubes(TiO_(2) NB).The Li_(2)FeTiO_(4) composites synthesized by HTO-NW shows a primary particle size of 50-200 nm of high crystallinity staggered with undissolved nanowire with a diameter size of about 100 nm.The samples using one-dimensio nal nanometer titanium oxide(TiO2 NB)as the raw material can get a super high initial discharge capacity of 367.8 mAh/g at the rate of C/10 and excellent cycling stability.The selection of raw materials and adopting multi-phase modification can be considered as an effective strategy to improve the electro-chemical properties of Li_(2)FeTiO_(4) composite cathode materials for the lithium secondary battery.