Cathode Materials For Lithium-ion Batteries Research Articles

Multifunctional ZnO/graphene co-coating on LiNi0.5Co0.2Mn0.3O2 cathode material for improving high voltage electrochemical performances

Layered nickel-rich LiNixCoyMn1-x-yO2 (NCM, x ≥ 0.5) is considered a promising cathode material for lithium-ion batteries (LIBs) with high energy density. However, the cycling stability and rate capability of the material degrades due to lattice distortion and phase change upon operating at high voltage. In this work, the surface co-coated with ZnO/graphene successfully enhanced the electrochemical performances of cathode material at high voltage ranges. As a result, the co-coating layer accelerates the diffusion of lithium ions, promoting electron migration, suppressing the side reaction between electrodes and electrolytes, and structural deterioration. The co-coating sample had a higher discharge capacity of 185.8 mAh g−1 and retention rate of 90.8% than those of the pristine (166.7 mAh g−1 and 82.4 %) after 200 cycles at 1 C (1C = 180 mAh g−1) at high voltage range.

Elevating cycle stability of Ni-rich NCM811 cathode via single-crystallization integrating dual-modification strategy for lithium-ion batteries

Nickel-rich layered oxide LiNi0.8Co0.1Mn0.1O2 (NCM811), as an attractive next-generation cathode material for lithium-ion batteries, still encounters grievously poor cycling stability triggered by irreversible phase transition in the layered structure and side reactions at the particle surface. Herein, a straightforward sol-gel method was proposed to fabricate highly stable Na+-doped and carbon-coated NCM811 single crystal, where the sodium glutamate acts as the common source of carbon-coating and Na+-doping. The Na ions prefer to occupy Li-sites that can lower the Li+ diffusion energy barrier and raise the threshold energy of Ni2+/Li+ irreversible migration to facilitate boosting Li+ migration rate and structural reversibility, as confirmed by theoretical calculation in conjunction with experimentation. And the carbon coating constructs a protective layer to effectively suppress parasitic reactions at the particle surface for enhancing cycling stability upon cycles. Consequently, the modified NCM-1 cathode displays the initial discharge capacity of 213.8 mAh·g−1 at 0.1 C and distinguished cycling stability at 5 C after 500 cycles with only approximately 0.034% capacity fading per cycle, which will be a strong competitive cathode material for developing high-power and long-lifespan lithium-ion batteries.

Stabilizing Ni-rich layered cathode for high-voltage operation through hierarchically heterogeneous doping with concentration gradient

High-nickel LiNixMnyCo1-x-yO2 (NMC) cathodes have demonstrated superior energy density, yet their stability is compromised under high voltage conditions. To address this, we propose a strategy of heterogeneous doping with a concentration gradient, specifically through Sr–Zr co-modification. We synthesized Ni-rich NMC particles featuring several micron-sized secondary particles composed of micron-sized primary grains. This design aims to harness the structural robustness of single-crystalline grains and the favorable diffusion kinetics of polycrystalline secondary particles. Systematic characterization using a combination of electrochemical measurements and synchrotron analytics reveals an intriguing pattern of hierarchically heterogeneous Sr–Zr co-doping. It demonstrates a depth-dependent concentration gradient at the secondary particle level and competing dopant segregation over the buried grain boundaries. This unique characteristic creates opportunities for enhancing battery performance, particularly by optimizing precursors and implementing advanced modulation techniques. We also investigate the dissolution and precipitation of the cathode's transition metal cations upon high-voltage cycling. These insights suggest that a tailored compositional variation can be a viable approach to effectively design the next-generation high-Ni NMC cathode materials for high-voltage lithium batteries.

The latest research on the pre-treatment and recovery methods of spent lithium-ion battery cathode material

The latest research on the pre-treatment and recovery methods of spent lithium-ion battery cathode material

Enhanced Performance of Li-Rich Manganese Oxide Cathode Synergistically Modificated by F-Doping and Oleic Acid Treatment.

Even lithium-rich manganese oxides (LRMOs) are considered as promising cathode materials for next-generation lithium-ion batteries, their commercialization is hindered mainly by the low initial Coulombic efficiency, poor cyclability and unexpected capacity fade. Here, a synergistic modification strategy by using both F doping and weak organic acid surface treatment is proposed to improve the electrochemical performances of LRMOs significantly. Optimized Li1.2 Mn0.54 Ni0.13 Co0.13 O1.95 F0.05 sample with surface oxygen vacancy defects and thin carbon coating layer exhibits profound electrochemical performances, for example, discharging capacities of 298.6 and 212.5 mAh g-1 at 0.1 C and 1 C rate, respectively. In addition, it can own an initial Coulombic efficiency of 84.4%, which is much higher than that of untreated sample. In situ X-ray diffractionanalysis implies that synergistic modification can enhance the skeleton stability of LRMOs , especially at a high state of charge. Galvanostatic intermittent titration technique analysis suggests that as-developed synergistic modification can accelerate the lithium ions diffusion. Theoretical calculations reveal that substituted F and oxygen vacancy defects can diminish the diffusion energy barrier of Li+ ions. This work provides a new synergistic modification strategy to improve the comprehensive properties of LRMO cathode effectively.

Distinctive interphasial properties and high structural reversibility endowed by B-/CN– electrolyte additive and its superior electrochemical performance for graphite/LiCoO2 pouch cells

The exploration of high energy density batteries requires cathodes with a high specific capacity and high voltage. LiCoO2 (LCO), a prospective cathode material for lithium-ion batteries (LIBs), displays a decent capacity but without a compatible electrolyte to withstand its high voltage. To create an enduring cathode electrolyte interphase (CEI), a novel electrolyte additive, 2-cyanophenylboronic acid (CBB), which possesses both cyano (CN–) and boronic acid (B-) functional group, is firstly put forward to be applied in LCO/Li cells as well as graphite/LCO pouch cell. Data from experimental and theoretical research both reveal that CBB preferentially decomposes on LCO surface, constructing a thin, robust and homogeneous CEI film rich in B-F/B-O species with fast kinetics and low impedance, suppressing the LCO surface transformation upon cycling due to the alleviated Co dissolution. CBB additive can enhance the structural reversibility (in-situ X-ray diffraction), decrease the electrolyte decomposition and eliminate the HF formation, constructing a much smoother surface than base electrolyte. LCO/Li cells with 1% CBB deliver more excellent capacity retention (96%) and a much superior rate capability (145 mAh/g, 5C) than that of base electrolyte (67%, 115 mAh/g). Intriguingly, graphite/LCO pouch batteries containing 1% CBB for 300 cycles deliver more outstanding capacity retention of 80% than that of base electrolyte (2%). This work reveals that CBB can function as an efficient electrolyte additive for high voltage LCO cathode, of which its distinctive CEI modification on the LCO surface provides valuable perspectives for its commercial application towards high energy density LIBs.

Lithium Storage Mechanism: A Review of Perylene Diimide N-Substituted with a 1,2,4-Triazol-3-yl Ring for Organic Cathode Materials.

The demand for lithium-ion batteries (LIBs) has increased rapidly. However, commercial inorganic-based cathode materials have a low theoretical capacity and inherent disadvantages, such as high cost and toxicity. Redox-active organic cathodes with a high theoretical capacity, eco-friendly properties, and sustainability have been developed to overcome these limitations. Herein, perylene diimide derivatives N-substituted with 1,2,4-triazol-3-yl rings (PDI-3AT) were developed to apply as a cathode material for LIBs. The PDI-3AT cathode exhibited discharge capacities of 85.2 mAh g-1 (50 mA g-1 over 100 cycles) and 64.5 mAh g-1 (500 mA g-1 over 1000 cycles) with ratios to the theoretical capacities of 84 and 64%, respectively. Electrochemical kinetics analysis showed capacitive behaviors of the PDI-3AT cathode with efficient pathways for lithium-ion transport. Also, the activation step of the PDI-3AT cathode was demonstrated by improving the charge transfer resistance and lithium-ion diffusion coefficient during the initial few charge-discharge cycles. Furthermore, DFT calculations at the B3LYP/6-311+G** level and ex situ analysis of various charge states of the PDI-3AT electrode using attenuated total reflection Fourier transform infrared (ATR FT-IR) analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were conducted for the further study of the lithium-ion storage mechanism. The results showed that the lithiation process formed the lithium enolate (═C-O-Li) coordinated with the N atoms of the 1,2,4-triazole ring. It is expected that our study results will encourage the production and use of redox-active perylene diimide derivatives as next-generation cathode materials.

Conjugated microporous polymers with multiple redox-active sites as anode and cathode materials for symmetric all-organic lithium-ion batteries

Due to their low solubility, tunable structure and multiple pore channels, conjugated microporous polymers (CMPs) are considered ideal electrode materials for green lithium-organic batteries (LOBs). Herein, two kinds of hexaazatrinnphthalene (HATN)-based CMPs (PHATN-CMP and HAKH-CMP) were designed and successfully synthesized by direct polycondensation and studied their electrochemical properties as both cathode/anode active materials for LOBs. In contrast, PHATN-CMP as the cathode material exhibits higher initial capacity of 169.6 mAh g−1 than that of HAHK-CMP at 50 mA g−1. In addition, as an anode material, PHATN-CMP also has a high initial capacity (1696.4 mAh g−1 at 50 mA g−1) and long cycle stability (retention of 870.5 mAh g−1 after 1000 cycles at 1 A g−1). More interestingly, all organic batteries assembled with PHATN-CMP as anode and cathode materials also show good electrochemical performance, which can light small light bulbs. This work will provide important insights into the design and application of electroactive CMPs for LOBs, even symmetrical all organic batteries.

Recycling different crystal forms of MnO2 from spent Li-ion batteries cathodes for SDZ degradation

Environmental pollution due to antibiotics usage and spent Li-ion batteries is escalating. To solve this issue, MnO2 with different crystalline phases were prepared as catalysts (recovered from spent lithium-ion battery cathode materials) for the degradation of sulfadiazine (SDZ) in this study by acid leaching and hydrothermal methods, respectively. The morphological and structural characteristics of catalysts were examined by XRD, SEM, XPS, and BET. The catalyst MnO2-6 h (β-MnO2) synthesized in six hours by hydrothermal method showed higher performance in destroying SDZ compared to MnO2-3 h (λ-MnO2) obtained by acid leaching method. Over 95% of SDZ was degraded by 0.2 g/L MnO2-6 h, 1 mM peroxymonosulfate (PMS) at pH 6 by pseudo-first-order kinetics. Density Functional Theory (DFT) calculations and related experimental analyses revealed that the main ROS within the MnO2-6 h/PMS system is SO4－·, which contributes about 67.49% to the degradation of SDZ. The high crystallinity and high Mn(III) ratio of MnO2-6 h are the key to the high catalytic activity of MnO2-6 h, which is highly stable and has potential for practical wastewater treatment. The study provides a new approach to managing the solid waste of spent Li-ion batteries and controlling emerging pollutants resulting from heavy antibiotic use.

Rational Molecular Design of Redox-Active Carbonyl-Bridged Heterotriangulenes for High-Performance Lithium-Ion Batteries.

Carbonyl aromatic compounds are promising cathode candidates for lithium-ion batteries (LIBs) because of their low weight and absence of cobalt and other metals, but they face constraints of limited redox-potential and low stability compared to traditional inorganic cathode materials. Herein, by means of first-principles calculations, a significant improvement of the electrochemical performance for carbonyl-bridged heterotriangulenes (CBHTs) is reported by introducing pyridinic N in their skeletons. Different center atoms (B, N, and P) and different types of functionalization with nitrogen effectively regulate the redox activity, conductivity, and solubility of CBHTs by influencing their electron affinity, energy levels of frontier orbitals and molecular polarity. By incorporating pyridinic N adjacent to the carbonyl groups, the electrochemical performance of N-functionalized CBHTs is significantly improved. Foremost, the estimated energy density reaches 1524Wh kg-1 for carbonyl-bridged tri (3,5-pyrimidyl) borane, 50% higher than in the inorganic reference material LiCoO2 , rendering N-functionalized CBHTs promising organic cathode materials for LIBs. The investigation reveals the underlying structure-performance relationship of conjugated carbonyl compounds and sheds new lights for the rational design of redox-active organic molecules for high-performance lithium ion batteries (LIBs).

Ultrathin VO2(B) nanosheets assembled into 3D micro/nano structured flower-like microspheres for high-performance cathode materials of Li-ion batteries

Vanadium oxides, as a potential cathode material for lithium-ion batteries (LIBs), have received extensive attention from researchers owing to their significant advantages in terms of theoretical specific capacity, energy density, and power density. However, vanadium oxides lead to irreversible decay of specific capacity during cycling for reasons such as poor structural stability and electrical conductivity. In this paper, the flower-like VO2(B) microsphere assembled from ultrathin nanosheets was synthesized successfully by hydrothermal method, and their effects on the morphology as well as the phase of VO2(B) are investigated by varying the hydrothermal reaction time and the concentration of oxalic acid. The results show that the flower-like VO2(B) microsphere electrode material not only provides a larger active area, but also offers a faster lithium ion diffusion rate and a shorter charge transport path, resulting in a high reversible capacity, outstanding rate performance, and excellent long cycle life. The flower-like VO2(B) microsphere electrode exhibited a first discharge specific capacity of 282.9 mAh/g (at a current density of 0.1 A/g) and a capacity retention of 80.7 % after 50 cycles. In addition, the electrode material shows a first discharge specific capacity of 209.6 mAh/g at a high current density (1 A/g) and a capacity retention rate of 83.1 % after 200 cycles. Consequently, the VO2(B) provides great development potential as a cathode material for next-generation LIBs.

Recent advancements in hydrometallurgical recycling technologies of spent lithium-ion battery cathode materials

Recent advancements in hydrometallurgical recycling technologies of spent lithium-ion battery cathode materials

Facile synthesis of FeF3•0.33H2O@3D N-doped carbon microspheres via self-assembly: An examination of electrochemical cathode dynamics in lithium-ion batteries

The theoretical capacity of FeF3 is 712 mAh g−1, making it a potential candidate as the next-generation cathode material of lithium-ion battery. However, FeF3 suffers from poor electronic/ion conductivity and poor kinetics. In this study, FeF3⋅0·33H2O@3D N-doped carbon nanofibrous microspheres (referred to as FF@CM) were prepared by EDTA self-assembly with chitosan fibers/Fe3+ sources, then carbonization and in-situ fluorination. The ultrafine FeF3⋅0.33H2O nanoparticles with an average diameter of 4.42 nm were found embedded in the 3D N-doped carbon microspheres. The FF@CM cathode delivers an initial discharge capacity of 353.57 mAh g−1 at 0.2C with a capacity decay rate of 6.77 % after 25 cycles, outperforming the bare FF cathode (with an initial discharge capacity of 263.92 mAh g−1 and a capacity decay rate of 35.95 %), the reversible capacities of the FF@CM and bare FF electrodes after 200 cycles at 0.2C are 96.29 and 4.75 mAh g−1, the pseudocapacitive contribution is up to 64 % for the FF@CM cathode at 1.0 mV s−1. The specific discharge capacities of FF@CM at 0.1, 0.2, 0.5, and 1C were 477.57, 432.15, 309.87 and 233.37 mAh g−1. Upon returning the rate to 0.1C, FF@CM recovered to the 79.23 % of the original capacity. The excellent electrochemical dynamics are attributed to its better electrolyte wettability and electronic conductivity of 3D porous microspheres, which have key contributions to advanced pseudo-capacitive behavior.

Sol-Gel synthesis and crystalline size, dislocation density and microstrain of LiNi0.85Co0.10Mn0.05O2 cathode material for lithium-ion batteries

Lithium-ion batteries (LIBs) are essential energy storage solutions for a wide range of applications. The cathode material significantly influences the performance of LIBs. Nickel-cobalt-manganese (NCM) ternary cathode materials have gained prominence due to their potential to offer high capacity, stability and voltage characteristics. In this paper, we focus on the synthesis of NCM cathode material using sol-gel method and its characterization primarily through X-ray diffraction (XRD) analysis. The crystal structure of the synthesized material is investigated using XRD. These XRD patterns are analyzed to estimate particle size and to deduce crystalline size, dislocation density and microstrain. This study helps us better understand how NCM materials are put together, which is important for making high performance lithium-ion batteries. These batteries are used in laptops, electric cars, etc.

Selective electrodeposition of Co-Ni alloys from synthetic quasi LiB NMC 532 cathode sulphate solutions using rotating plate potentiostatic electrowinning

The interest in recycling spent lithium-ion batteries (Li-ionB) has surged due to the rising demand for valuable metals (e.g., Co, Ni, Li and Mn) and concerns about environmental repercussions emanating from conventional battery waste disposal. This research is centered on the recovery of the valuable Ni-Co alloys from synthetic Ni, Co, Mn and Li sulphate solutions mimicking the NMC 532 ratio of elements using a hydro-electrometallurgy process route that integrates hydrometallurgy and potentiostatic electrometallurgy techniques. This quasi-model is done to elucidate the effect of multiple influencing parameters, through isolation and varying, on the selective electrodeposition of Co-Ni from multi-ion (Li, Ni, Mn and Co) complex solutions before applying it using real cathode leachates. The selective electrowinning metal recovery process route is a cost-effective alternative to the energy, cost and material-intensive hydrometallurgy intermediate purification processes such as solvent extraction, selective precipitation, and ion-exchange. The study delves into the effects of various electrowinning parameters, including applied potential, temperature, pH, Co, Ni, Na2SO4, NaH2PO4 buffer concentration, and cathode rotational speed. These parameters were thoroughly investigated and effectively optimised to achieve the recovery of 98.2% pure Ni0.65Co0.35 at a rate of 0.060 g/cm2.h with an impressive 89.25 % current efficiency. The composition of the electrowon deposit was meticulously quantified using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and subjected to analysis through a Scanning Electron Microscope (SEM-EDS). Additionally, the phase composition was evaluated using X-Ray Diffraction analysis (XRD). The results successfully demonstrate the technical feasibility of recovering Ni-Co alloys, yielding high quantities of industrial-grade pure Ni-Co alloys. This comprehensive electro-hydrometallurgical process, designed for both closed and loop recycling purposes, promotes a more environmentally preservative approach to recycling spent lithium-ion battery cathode material. The approach contributes significantly to the development of sustainable resource management infrastructure.

Developing rapid electrochemical relithiation protocols for scalable relithiation of lithium-ion battery cathode materials

The recent and ongoing boom in electric vehicle sales has caused the circularity of the supply chain for electric vehicle battery materials to come under a great deal of scrutiny. Innovative recycling processes, or direct recycling, that offer the possibility of reducing the cost of recycling are one possible solution to regaining resources from end-of-life (EoL) electric vehicle batteries. Electrochemically shuttling lithium back into the cathode, or electrochemical relithiation, is a possible technique for restoring lithium content to NMC materials (EoL) in a direct recycling process. This study provides essential understanding towards developing an electrochemical relithiation protocol that will restore lithium loss in intercalation cathode materials that reach EoL by loss of lithium inventory (LLI) as opposed to other degradation mechanisms like loss of active material (LAM), cation mixing or phase transition. Electrochemically aged NMC cathode materials have been prepared and characterized to establish the extent of EoL material structural degradation and lithium loss. A model-informed experimental process is used to identify the optimal electrochemical relithiation protocol to minimize the time taken to relithiate EoL materials and maximize the amount of lithium restored. Protocols were evaluated based on their ability to enable rapid lithium intercalation, maintain structural uniformity in the EoL material and fully restore lithium content. An optimal protocol was identified at elevated temperatures utilizing a novel scanning voltage step.

Multifunctional surface structure with enhanced electron and ion conductivities for superior electrochemical performance of Co-free Li-rich Mn-based layered oxide cathodes

Co-free Li-rich Mn-based layered oxides (LRMLOs) are attractive cathode materials for lithium-ion batteries due to their low cost, high energy density and environmental friendliness. However, they also suffer from the drawbacks of low initial Coulombic efficiency, rapid voltage fading and capacity decay, and poor rate performance as the general LRMLO cathode, which prevent their practical applications. In the present work, a multilayer surface coating composed of Li2B4O7/B2O3 and a spinel heterostructure rich-in oxygen vacancies are in-situ formed at the surface of the Co-free LRMLO particles by a facile thermal reduction treatment with NH4B5O8. The multilayer surface improves greatly the electron and ion conductivities, and plays significantly synergistic roles on suppressing oxygen release, reducing the dissolution of Mn and Ni elements, retarding the structure transformation from layered to spinel, and preventing the side reaction of the active material with electrolyte during cycling for the cathodes. As a result, the overall electrochemical properties of the cathodes are significantly improved. With an optimized addition of 10 wt% NH4B5O8, the initial Coulombic efficiency of the cathode is as high as 90.0%, and a capacity of 275 mAh g-1 is obtained at 0.1 C (1 C = 200 mA g-1) with the capacity retention of 98.5% after 100 cycles. A capacity of 194 mAh g-1 is maintained after 300 cycles at 1 C, with the capacity retention of 92.8%. A capacity of 117 mAh g-1 is obtained at a high rate of 20 C. In addition, the voltage fading during cycling is also greatly inhibited. The structure evolution of the cathode material during cycling is systematically investigated and the mechanism for the improved electrochemical properties is proposed. The present work provides a new surface structure design strategy and the method for enhancing the overall electrochemical performance of Co-free Li-rich Mn-based layered oxide cathodes.

From Silica Leachate of Laterite Nickel Ore to Silicate Cathode Material: Preparation of Li2MnSiO4/C as Lithium-ion Battery Cathode Material by Two-Stage Roasting Method

From Silica Leachate of Laterite Nickel Ore to Silicate Cathode Material: Preparation of Li2MnSiO4/C as Lithium-ion Battery Cathode Material by Two-Stage Roasting Method

High-Performance Single-Crystal Lithium-Rich Layered Oxides Cathode Materials via Na2WO4-Assisted Sintering.

Single-crystal lithium-rich layered oxides (LLOs) with excellent mechanical properties can enhance their crystal structure stability. However, the conventional methods for preparing single-crystal LLOs, require large amounts of molten salt additives, involve complicated washing steps, and increase the difficulty of large-scale production. In this study, a sodium tungstate (Na2WO4)-assisted sintering method is proposed to fabricate high-performance single-crystal LLOs cathode materials without large amounts of additives and additional washing steps. During the sintering process, Na2WO4 promotes particle growth and forms a protective coating on the surface of LLOs particles, effectively suppressing the side reactions at the cathode/electrolyte interface. Additionally, trace amounts of Na and W atoms are doped into the LLOs lattice via gradient doping. Experimental results and theoretical calculations indicate that Na and W doping stabilizes the crystal structure and enhances the Li+ ions diffusion rate. The prepared single-crystal LLOs exhibit outstanding capacity retention of 82.7% (compared to 65.0%, after 200 cycles at 1C) and a low voltage decay rate of 0.76mV per cycle (compared to 1.80mV per cycle). This strategy provides a novel pathway for designing the next-generation high-performance cathode materials for Lithium-ion batteries (LIBs).

Opportunities and Challenges of Layered Lithium-Rich Manganese-Based Cathode Materials for High Energy Density Lithium-Ion Batteries

Opportunities and Challenges of Layered Lithium-Rich Manganese-Based Cathode Materials for High Energy Density Lithium-Ion Batteries