Cathode Materials For Lithium-ion Batteries Research Articles

Metal recovery from spent lithium-ion batteries cathode materials: Comparative study of sugar-based reductants

Sugars and sugar-rich agricultural by-products are cheaper and eco-friendly alternatives to conventional reductants used in recovering metals from spent lithium-ion batteries. Still, they are rarely used due to a poor understanding of their performance and reaction chemistry. In this study, two hypotheses bearing on the role of chemistry and influence of non-sugary organic compounds (impurities) on the performance of sugars, namely: glucose, fructose and sucrose, and a parent sugar-rich agro-industrial by-product – molasses, as reductants in the leaching of Li, Co, Mn and Ni from spent lithium-ion battery cathode material were tested. Statistical analysis using ANOVA revealed that the performance of the sugars and molasses are similar with >85% Mn, >88% Ni, >88%Co and >98% Li leached at 90 °C and 60 min. This shows that the presence of non-sugar organic compounds does not hamper the performance of the sugars-based reductants. The performance of the sugars relies more on temperature than chemistry. Furthermore, evaluation of the oxidation pathway hints at a potential inhibition of secondary oxidation reactions at lower temperatures. This study provides statistically validated proof that the performance of sugarcane molasses, even at lower concentration, is equipollent to the pure sugars in the leaching of critical metals from spent lithium-ion batteries.

The capacity fading mechanism of high-capacity CrOx (x ≥ 2.5) cathode material for lithium-ion battery

The capacity fading mechanism of high-capacity CrOx (x ≥ 2.5) cathode material for lithium-ion battery

Unveiling the tailorable electrochemical properties of zeolitic imidazolate framework-derived Ni-doped LiCoO2 for lithium-ion batteries in half/full cells

As a prevailing cathode material of lithium-ion batteries (LIBs), LiCoO2 (LCO) still encounters the tricky problems of structural collapse, whose morphological engineering and cation doping are crucial for surmounting the mechanical strains and alleviating phase degradation upon cycling. Hereinafter, we propose a strategy using a zeolitic imidazolate framework (ZIF) as the self-sacrificing template to directionally prepare a series of LiNi0.1Co0.9O2 (LNCO) with tailorable electrochemical properties. The rational selection of sintering temperature imparts the superiority of the resultant products in lithium storage, during which the sample prepared at 700 °C (LNCO-700) outperforms its counterparts in cyclability (156.8 mA h g−1 at 1 C for 200 cycles in half cells, 1 C = 275 mA g−1) and rate capability due to the expedited ion/electron transport and the strengthen mechanical robustness. The feasibility of proper Ni doping is also divulged by half/full cell tests and theoretical study, during which LNCO-700 (167 mA h g−1 at 1 C for 100 cycles in full cells) surpasses LCO-700 in battery performance due to the mitigated phase deterioration, stabilized layered structure, ameliorated electronic conductivity, and exalted lithium storage activity. This work systematically unveils tailorable electrochemical behaviors of LNCO to better direct their practical application.

Improving Fast-Charging Capability of High-Voltage Spinel LiNi0.5Mn1.5O4 Cathode under Long-Term Cyclability through Co-Doping Strategy.

Co-free spinel LiNi0.5Mn1.5O4 (LNMO) is emerging as a promising contender for designing next generation high-energy-density and fast-charging Li-ion batteries, due to its high operating voltage and good Li+ diffusion rate. However, further improvement of the Li+ diffusion ability and simultaneous resolution of Mn dissolution still pose significant challenges for their practical application. To tackle these challenges, a simple co-doping strategy is proposed. Compared to Pure-LNMO, the extended lattice in resulting LNMO-SbF sample provides wider Li+ migration channels, ensuring both enhanced Li+ transport kinetics, and lower energy barrier. Moreover, Sb creating structural pillar and stronger TM─F bond together provides a stabilized spinel structure, which stems from the suppression of detrimental irreversible phase transformation during cycling related to Mn dissolution. Benefiting from the synergistic effect, the LNMO-SbF material exhibits a superior reversible capacity (111.4mAhg-1 at 5C, and 70.2mAhg-1 after 450cycles at 10C) and excellent long-term cycling stability at high current density (69.4% capacity retention at 5C after 1000cycles). Furthermore, the LNMO-SbF//graphite full cell delivers an exceptional retention rate of 96.9% after 300cycles, and provides a high energy density at 3C even with a high loading. This work provides valuable insight into the design of fast-charging cathode materials for future high energy density lithium-ion batteries.

Cation mixing regulation of cobalt-free high-nickel layered cathodes enables stable and high-rate lithium-ion batteries

The cobalt-free high-nickel layered oxide possesses high capacity and controllable cost, positioning it as a prospective option for cathode materials in the future lithium-ion batteries (LIBs). However, the charge compensation effect and high nickel content usually cause serious cation mixing, resulting in poor capacity stability, and hindering its practical application. Here, three types of LiNi0.9Mn0.1O2 microspheres with varying levels of cation mixing are constructed by simply adjusting the calcination temperatures, and the impacts of cation mixing on the electrochemical performance in LIBs are systematically investigated. By using XRD and cross-section STEM to characterize the levels of cation mixing, the resulting LiNi0.9Mn0.1O2 after treated at 780 °C (denoted as NM91–780) shows a lower degree of cation mixing compared to other samples (NM91–720 and NM91–840). As a proof-of-concept application in LIBs, the NM91–780 exhibits remarkable cycling stability with 92.4% capacity retention after 100 cycles, along with excellent rate capability of 132.5 mAh g−1 at 10 C. In situ XRD analysis shows that the low cation mixing of NM91–780 inhibits harmful volumetric strain during the electrochemical process, providing structural and chemical stability for its long-term cycling. This investigation contributes to the advancement of commercializing cobalt-free high-nickel layered oxide LiNi0.9Mn0.1O2 for use in LIBs.

Ni/Mg Dual Concentration-Gradient Surface Modification to Enhance Structural Stability and Electrochemical Performance of Li-Rich Layered Oxides.

Li-rich layered oxides (LRLOs), with the advantages of high specific capacity and low cost, are considered as candidates for the next-generation cathode of lithium-ion batteries (LIBs). Unfortunately, sluggish kinetics and interfacial degradation lead to capacity loss and voltage decay of the material during cycling. To address these issues, we propose a Ni/Mg dual concentration-gradient modification strategy for LRLOs. From the center to the surface of the modified materials, the contents of Ni and Mg are gradually increased while the content of Mn is decreased. The high Ni content on the surface increases the proportion of cationic redox, elevating the operating voltage and accelerating reaction kinetics. Moreover, the doped Mg on the surface of the material acting as a stabilizing pillar suppresses the migration of transition metals, stabilizing the layered structure. Therefore, the material with the Ni/Mg dual concentration-gradients delivers a superior electrochemical performance, exhibiting a suppressed voltage decay of 2.8 mV per cycle during 200 cycles (1 C, 2-4.8 V) and an excellent rate capability of 94.84 mAh/g at 7C. This study demonstrates a synergic design to construct high-performance LRLO cathode materials for LIBs.

Numerical and experimental study on the calcination process of the raw materials of lithium battery cathode

Ternary cathode materials hold great promise in the lithium battery market, yet analyses regarding their calcination process in simulation and on-site experimentation, are few. In this paper, a multiphysics-coupled computational fluid dynamics (CFD) model was developed to simulate the primary calcination process (The actual production process is divided into two calcinations, because the production conditions affect the measurement, this paper focuses on the analysis of the primary calcination process) of lithium battery raw materials (namely, Ni0.8Co0.1Mn0.1(OH)2 and LiOH∙H2O mixture, hereinafter referred to as raw materials) under oxidizing atmosphere conditions. The process involves fluid flow, heat and mass transfer, and chemical reactions. A new method which combined steady-state calculation with transient calculation was adopted. Firstly, the steady-state simulation of the whole furnace was carried out, and then the transient simulation of each furnace area is carried out consequently, the heat and mass transfer processes of raw materials in different furnace zones were solved, ultimately achieving the simulation of the entire furnace calcination process. On-site black box experiments were performed to obtain the temperature evolution during the calcination process. Meanwhile, compared with the calculated results of the model, it was found that the average hit rate with an absolute error of less than ±20 °C above 300 °C can reach 86.9%, confirming the applicability of the model. The multiphysics-coupled CFD model simultaneously solves the oxygen concentration. The process parameters were analyzed based on the model, providing a fundamental method for the improvement of the performance of lithium battery cathode materials calcination process.

Reliable test by accelerating for gas evolution in cathode materials of lithium-ion batteries

Lithium-ion batteries are widely used in modern electronic devices and Electric Vehicles (EVs) and play an important role in various applications, but fire and explosion accidents continue to occur in Energy Storage Systems (ESSs) and EVs, which is an issue. Due to the material characteristics of the Li-ion battery, when charging and discharging are repeated, gas is generated not only due to structural changes inside the cell, but also due to various external factors. This can lead to an explosion accident of the battery cell. Therefore, gas generation in batteries is considered an essential problem to be solved for battery safety. However, accurate gas generation comparisons are possible only when the gas generation conditions and processes of the battery are established, and the conditions under which gas can be uniformly generated in the battery have not yet been investigated. According to previous studies, the main causes of gas generation are considered as follows. 1) Operating at high voltage range, 2) Operating at high temperature and 3) H2O present inside the cell. Therefore, this study conducted a study on the possibility of reproducing the above tree gas generations, which are considered to be a major cause of gas generation. Gas generation in high voltage operation and high temperature operation was confirmed, but there was no reliable reproducibility. On the other hand, it was confirmed that H2O inside the cell reproducibly generates gas. In addition, compared to the Al coating sample, a surface treatment that suppresses gas generation caused by HF generation by H2O, it was reliably confirmed that more than 10% of gas generation by H2O was prevented.

Advancements and Challenges in High-Capacity Ni-Rich Cathode Materials for Lithium-Ion Batteries.

Nowadays, lithium-ion batteries are undoubtedly known as the most promising rechargeable batteries. However, these batteries face some big challenges, like not having enough energy and not lasting long enough, that should be addressed. Ternary Ni-rich Li[NixCoyMnz]O2 and Li[NixCoyAlz]O2 cathode materials stand as the ideal candidate for a cathode active material to achieve high capacity and energy density, low manufacturing cost, and high operating voltage. However, capacity gain from Ni enrichment is nullified by the concurrent fast capacity fading because of issues such as gas evolution, microcracks propagation and pulverization, phase transition, electrolyte decomposition, cation mixing, and dissolution of transition metals at high operating voltage, which hinders their commercialization. In order to tackle these problems, researchers conducted many strategies, including elemental doping, surface coating, and particle engineering. This review paper mainly talks about origins of problems and their mechanisms leading to electrochemical performance deterioration for Ni-rich cathode materials and modification approaches to address the problems.

Diamino-Substituted Quinones as Cathodes for Lithium-Ion Batteries.

This study introduces a sustainable approach to designing organic cathode materials (OCMs) for lithium-ion batteries as a potential replacement for traditional metal-based electrodes. Utilizing green synthetic methodologies, we synthesized and characterized five distinct quinone derivatives and investigated their electrochemical attributes within Li-ion battery architectures. Notably, the observed specific capacities were lower than the theoretical predictions, suggesting limitations in achieving efficient redox reactions in a coin-cell configuration. Among the quinone derivatives studied, one variant derived from natural vanillin showed superior cycle stability, maintaining 58% capacity retention over 95 charge-discharge cycles, and achieving a Coulombic efficiency of 90%. Importantly, we discovered that the commonly used Super-P conductive carbon did not yield any measurable battery performance; instead, these quinones necessitated the incorporation of graphene nanoplatelets as the conductive matrix. Through a facile one-step synthesis in ethanol or water, we have demonstrated a viable synthetic route for producing OCMs, albeit with moderate performances, which have attempted to address common concerns of high solubility and poor redox reactivity of previous OCMs, thereby offering a sustainable pathway for the development of organic-based energy storage devices.

Li-ion storage performance of V10O24.nH2O microbelt as cathode material for lithium-ion battery

For the first time, we report the Li-ion storage performance of V10O24.nH2O with LiPF6 based liquid electrolyte (LE) and PDATFSI-60IL based solid-polymer electrolyte (SPE). The LiǁV10O24.nH2O in LE exhibits a reversible capacity of ∼184/83 mAh g−1 at 0.1/5.0 A g−1, respectively, and features good cycling stability (retained 98.78, and 65.53 % after 1000 and 2000 cycles, respectively). In case of solid-state Li-ion battery (ssLiB), the PDATFSI-60IL membrane is utilized as SPE as well as binder for V10O24.nH2O cathode material. The PDATFSI-based SPE effectively provides reliable Li+ conductive galleries, prevents the Li dendrites formation, and provides stable contact between the cathode and current collector. The resultant V10O24.nH2O cathode exhibit a reversible capacity of ∼152 mAh g−1 at 0.1 A g−1, demonstrating good rate performance (≈152/38 mAh g−1 at 0.1/5 A g−1) with considerable cycling stability (≈72 % capacity retention at 500th charge/discharge cycle).

Stabilizing Ni-rich Single-crystalline LiNi0.83 Co0.07 Mn0.10 O2 Cathodes using Ce/Gd Co-doped High-entropy Composite Surfaces.

Ni-rich layered oxides are promising lithium-ion batteries (LIBs) cathode materials for their high reversible capacity, but they suffer from fast structural degradation during cycling. Here, we report the Ce/Gd incorporated single-crystalline LiNi0.83 Co0.07 Mn0.10 O2 (SC-NCM) cathode materials with significantly enhanced cycling stability. The Gd ions are adequately incorporated in SC-NCM while Ce ions are prone to aggregate in the outer surface, resulting in the formation of a high-entropy zone in the near-surface of SC-NCM, including a Gd doped LiCeO2 (LCGO) shell and Ce/Gd dopant-concentrated layer. The high-entropy zone can effectively inhibit the oxygen evolution and prevent the formation of oxygen vacancies. Meanwhile, it leads to a greatly improved H2-H3 phase transformation reversibility and mitigated stress/strain caused by Li-ion extraction/insertion during (de)lithiation process. The synergetic effects of reduced oxygen vacancies concentration and mitigated stress/strain can effectively prevent the in-plane migration of TM ions, lattice planar gliding as well as the formation of intragranular nanocracks. Consequently, Ce/Gd incorporated SC-NCM (SC-NCM@CG2) delivers a high initial discharge specific capacity of 219.7 mAh g-1 at 0.1 C and an excellent cycling stability with a capacity retention of 90.2 % after 100 cycles at 1.0 C.

A facile eutectic mixed molten salt method for synthesizing LiNi0.5Co0.2Mn0.3O2 cathode material for lithium-ion batteries

LiNi0.5Co0.2Mn0.3O2 as a kind of layered oxide, has garnered significant interest due to its low cost and facile preparation method. Nevertheless, fast discharge capacity attenuation, poor cycle stability restricts it further application. To optimize its properties, in this paper, a novel eutectic mixed molten salt method is proposed to synthesize LiNi0.5Co0.2Mn0.3O2. The results demonstrate that the LiNi0.5Co0.2Mn0.3O2 obtained through LiOH-LiNO3 as eutectic mixed molten salt exhibited exceptional electrochemical properties. It had a reversible capacity of 151.7 mAh·g−1 after 100 cycles at 0.2 C, with a capacity retention of 89.3%, the discharge capacities of 165.6, 135.8, 121.8 and 111.2 mAh·g−1 at 0.5, 1.0, 2.0 and 5.0 C, respectively. This study highlights a convenient method for preparing LiNi0.5Co0.2Mn0.3O2 and demonstrates the effectiveness of the eutectic mixed molten salt approach in enhancing electrochemical properties.

Mn-doped LiFePO4@C as a high-performance cathode material for lithium-ion batteries

In this work, LiFe1-xMnxPO4@C (x = 0, 0.01, 0.02, 0.03) cathode materials were obtained by a simple co-precipitation method and heat treatment, and the influence of Mn-doped modification on the electrochemical performance of LiFePO4@C cathode materials was investigated. Results show that by doping an appropriate amount of Mn, the cell volume became larger, and the electronic conductivity increased, which improved the Li+ diffusion rate and thus its rate capability and cycle performance of Li-ion batteries. Among them, LiFe0.98Mn0.02PO4@C showed superior lithium storage capability; the discharge capacity can reach 150.7 mAh g−1 at 0.1 C. The cell could discharge up to 155.9 mAh g−1 at 1 C under high temperature at 45 °C, which was higher than LiFePO4@C (142 mAh g−1) under the same test conditions. The discharge capacity of 1 C at room temperature was 139.9 mAh g−1, and the cycle stability was 95.9% after 200 cycles. It showed that it had good rate capability and excellent cycle performance. These results indicate that Mn-doped LFP is a simple and effective strategy for developing high-performance cathode materials.

Exploring Organic Cathode Materials for Lithium-Ion Batteries through Fragment Bonding and Discharge Simulation

Exploring Organic Cathode Materials for Lithium-Ion Batteries through Fragment Bonding and Discharge Simulation

Synthesis and electrical properties of glassy and nanocrystalline LiFePO[formula omitted

Lithium iron phosphate (LFP) has been intensively studied as a cathode material for lithium-ion batteries. Mainly, polycrystalline or nanocrystalline LFP have been studied so far. Our approach is to synthesize glassy analogs of crystalline cathode materials and subject them to proper heat treatment to induce thermal nanocrystallization. In this paper, we attempted to synthesize amorphous LFP using the twin-rollers technique and improve its electrical properties. It was shown that in this approach LFP is on the verge of crystallization during quenching and most of the samples contained some traces of LFP crystallites. After optimization, the electrical conductivity of nanocrystalline samples reached ca. 10−5 S/cm at room temperature, and the activation energy decreased to 0.25 eV. Even though, the electrochemical performance of nanocrystalline LFP in laboratory Li cells in this work remained modest.

Hybrid Organosulfur Cathode Materials for Rechargeable Lithium Batteries

Hybrid Organosulfur Cathode Materials for Rechargeable Lithium Batteries

Glycerol solvothermal synthesis of high-performance lithium-ion battery cathode materials with surface oxygen vacancies

Glycerol solvothermal synthesis of high-performance lithium-ion battery cathode materials with surface oxygen vacancies

Phenyl Tellurosulfides as Cathode Materials for Rechargeable Lithium Batteries.

Phenyl ditelluride (PDTe) as a cathode material for rechargeable batteries has a low specific capacity (130.9 mAh g-1) due to limited active sites (two). To increase its capacity, additional active species need to be added to the structure of PDTe, like sulfur. Here, phenyl tellurosulfide (PDTeS) and phenyl tellurodisulfide (PDTeS2) can be formed via addition reactions and have specific capacities of 242.8 and 339.6 mAh g-1, respectively. The products are characterized by mass spectrometry and Raman spectroscopy. The Li/PDTeSn (n = 1-2) cells exhibit high material utilization (>85%) and unique redox mechanism. They can be cycled stably for more than 1000 cycles at an areal mass loading of 1.1 mg cm-2 and maintain capacity retentions of >72% after 100 cycles with PDTeSn loading of ∼6 mg cm-2. Moreover, the Li/PDTeS2 cell achieves a specific energy of up to 695 Wh kg-1 even when the electrolyte/PDTeS2 ratio is as low as 2.5 μL mg-1. The successful synthesis and application of PDTeSn prove that they are promising cathode materials for rechargeable lithium batteries.

Mg/Fe site-specific dual-doping to boost the performance of cobalt-free nickle-rich layered oxide cathode for high-energy lithium-ion batteries

Layer-type LiNi0.9Mn0.1O2 is promising to be the primary cathode material for lithium-ion batteries (LIBs) due to its excellent electrochemical performance. Unfortunately, the cathode with high nickel content suffers from severely detrimental structural transformation that causes rapid capacity attenuation. Herein, site-specific dual-doping with Fe and Mg ions is proposed to enhance the structural stability of LiNi0.9Mn0.1O2. The Fe3+ dopants are inserted into transition metal sites (3b) and can favorably provide additional redox potential to compensate for charge and enhance the reversibility of anionic redox. The Mg ions are doped into the Li sites (3a) and serve as O2−-Mg2+-O2− pillar to reinforce the electrostatic cohesion between the two adjacent transition-metal layers, which further suppress the cracking and the generation of harmful phase transitions, ultimately improving the cyclability. The theoretical calculations, including Bader charge and crystal orbital Hamilton populations (COHP) analyses, confirm that the doped Fe and Mg can form stable bonds with oxygen and the electrostatic repulsion of O2−-O2−can be effectively suppressed, which effectively mitigates oxygen anion loss at the high delithiation state. This dual-site doping strategy offers new avenues for understanding and regulating the crystalline oxygen redox and demonstrates significant potential for designing high-performance cobalt-free nickel-rich cathodes.