Cathode For Lithium Research Articles

Reductive coupling mechanism in layered oxide cathodes for lithium-/sodium-ion batteries

Reductive coupling mechanism in layered oxide cathodes for lithium-/sodium-ion batteries

In situ construction of sequential nanoreactor with built-in catalyst as self-supporting cathode for lithium–sulfur batteries

Architecture design and optimization are essential in improving the performance of lithium–sulfur batteries. Herein, an all-in-one sequential architecture of CoSe catalysts confined in MOF-derived nanoreactors (NRs) interfacially welded on carbon cloth (CC) is constructed using an in situ strategy (abbreviated: S@CoSe-NRs/CC). NRs with built-in CoSe (CoSe-NRs) have special microenvironments and domain-limited catalysis for efficient adsorption, catalysis, and deposition. The weld interface between the CoSe-NRs and the CC forms a continuous and robust all-in-one conductive network. Both experiments and theoretical calculations demonstrate that the S@CoSe-NRs/CC offers stable interconnectivity and efficient space utilization for high sulfur loads and rapid ion transport supply, providing a high initial discharge capacity of 1320 mA h g−1 at 0.1 C with a capacity decay rate as low as 0.003% per turn after 1000 cycles. This study offers unique insights and revelations for realizing the rational design of high-performance energy storage devices.

2D Covalent Organic Framework Covalently Anchored with Carbon Nanotube as High-Performance Cathodes for Lithium and Sodium-Ion Batteries.

Covalent organic frameworks (COFs), featuring structural diversity, permanent porosity, and functional versatility, have emerged as promising electrode materials for rechargeable batteries. To date, amorphous polymer, COF, or their composites are mostly explored in lithium-ion batteries (LIBs), while their research in other alkali metal ion batteries is still in infancy. This can be due to the challenges that arise from large volume changes, slow diffusion kinetics, and inefficient active site utilization by the large Na+ or K+ ion. Herein, microwave-assisted imide-based 2D COF, TAPB-NDA covalently connected with amine-functionalized carbon nanotubes (TAPB-NDA@CNT) targeting the application in both Li-/Na-ion batteries, is synthesized. As-synthesized, TAPB-NDA@CNT50 displays the good performance as LIB cathode with a specific capacity of ≈138mAhg-1 at 25mAg-1, long cycling stability (81.2% retention after 2000 cycles at 300mAg-1), with excellent reversible capacity retention of ≈79.6%. Similarly, TAPB-NDA@CNT50, when employed in sodium-ion battery (SIB), exhibited 136.7mAhg-1 specific capacity at 25mAg-1, retained ≈80% of the reversible capacity after 1000 cycles at 300mAg-1 and showing excellent rate performance. The structural advantage of TAPB-NDA@CNT will encourage researchers to design COF-based cathodes for the alkali ion batteries.

Scalable Ni12P5-Coated Carbon Cloth Cathode for Lithium–Sulfur Batteries

As a better alternative to lithium-ion batteries (LIBs), lithium–sulfur batteries (LSBs) stand out because of their multi-electron redox reactions and high theoretical specific capacity (1675 mA h g−1). However, the long-term stability of LSBs and their commercialization are significantly compromised by the inherently irreversible transition of soluble lithium polysulfides (LiPS) into solid short-chain S species (Li2S2 and Li2S) and the resulting substantial density change in S. To address these issues, we used activated carbon cloth (ACC) coated with Ni12P5 as a porous, conductive, and scalable sulfur host material for LSBs. ACC has the benefit of high electrical conductivity, high surface area, and a three-dimensional (3D) porous architecture, allowing for ion transport channels and void spaces for the volume expansion of S upon lithiation. Ni12P5 accelerates the breakdown of Li2S to increase the efficiency of active materials and trap soluble polysulfides. The highly effective Ni12P5 electrocatalyst supported on ACC drastically reduced the severity of the LiPS shuttle, affected the abundance of adsorption–diffusion–conversion interfaces, and demonstrated outstanding performance. Our cells achieved near theoretical capacity (>1611 mA h g−1) during initial cycling and superior capacity retention (87%) for >250 cycles following stabilization with a 0.05% decay rate per cycle at 0.2 C.

High-Voltage, High Capacity Aluminum-Rich Lithium Cathode Materials: A Bayesian Optimization and First-Principles Study

High-Voltage, High Capacity Aluminum-Rich Lithium Cathode Materials: A Bayesian Optimization and First-Principles Study

Role of site–specific doping in stabilizing high–nickel cathodes for high-performance lithium- ion -batteries

The growing demand for high-capacity and energy-dense lithium-ion batteries has driven the increase of nickel content in commercially available cathodes. However, during deep charging (delithiation), these Ni-rich cathodes experience a detrimental phase transformation and a sudden, significant decrease in lattice volume. This lattice collapse is considered the primary culprit behind the limitations in the cathode's electrochemical performance. Notably, the exact cause-and-effect relationship between the phase change and the collapse remains unclear. In the present study, the effect of the site of substitution on the performance of the LiNiO2 cathode has been investigated by adopting tungsten as a dopant. To gain deeper insights into this connection within Ni-rich LiNiO2, the contraction of the c-axis and the change in the a-axis during the delithiation have been investigated using ab initio density functional theory. Findings reveal that the free energy difference between the suspected phases in Ni-rich LiNiO2 is minimal at room temperature, facilitating the transition from the H2 to the H3 phase. This transition appears to be driven by the movement (gliding) of the NiO2 layer towards the adjacent Li layer. The findings of the present study indicate that among two different configurations due to different sites of substitution, the WLNO-2 configuration suppresses H2 –H3 phase conversion to a greater extent by hindering the gliding of the NiO2 layer toward the Li layer. Furthermore, a reduction in the collapse of the c-axis lattice during deep de-lithiation for the WLNO-2 configuration has been observed. This reduced collapse is primarily attributed to the altered charge distribution within oxygen atoms and the weakened screening effect from lithium ions.

Lightweight Electrolyte Design for Li/Sulfurized Polyacrylonitrile (SPAN) Batteries.

Sulfurized polyacrylonitrile (SPAN) recently emergesas a promising cathode for high-energy lithium (Li) metal batteries owing to its high capacity, extended cycle life, and liberty from costly transition metals. As the high capacities of both Li metal and SPAN lead to relatively small electrode weights, the weight and specific energy density of Li/SPAN batteries are particularly sensitive to electrolyte weight, highlighting the importance of minimizing electrolyte density. Besides, the large volume changes of Li metal anode and SPAN cathode require inorganic-rich interphases that can guarantee intactness and protectivity throughout long cycles. This work addresses these crucial aspects with an electrolyte design where lightweight dibutyl ether (DBE) is used as adiluent for concentrated lithium bis(fluorosulfonyl)imide(LiFSI)-triethyl phosphate (TEP) solution. The designed electrolyte (d = 1.04g mL-1) is 40%-50% lighter than conventional localized high-concentration electrolytes (LHCEs), leading to 12%-20% extra energy density at the cell level. Besides, the use of DBE introduces substantial solvent-diluent affinity, resulting in a unique solvation structure with strengthened capability to form favorable anion-derived inorganic-rich interphases, minimize electrolyte consumption, and improve cell cyclability. The electrolyte also exhibits low volatility and offers good protection to both Li metal anode and SPAN cathode under thermal abuse.

Incorporation of electronically and ionically conductive additives in high-loading sulfur cathodes in lean-electrolyte lithium–sulfur cells

Low-cost, high-energy-density lithium–sulfur electrochemical batteries have emerged as a promising solution for next-generation energy-storage technologies. To facilitate the practical application of such batteries, it is necessary to address the remaining scientific and engineering challenges, especially those associated with the high-loading sulfur cathode in a lean-electrolyte cell. In this study, we investigate the electrochemical and overall performance of lithium–sulfur cells with a high-loading sulfur cathode. Notably, this cathode is fabricated using a novel hot-pressing method and incorporates electronically and ionically conductive additives, specifically lithium lanthanum titanate (LLTO) and carbon black, respectively. Material analysis reveals the uniform distribution of additives in the cathodes, with the ionically conductive LLTO effectively adsorbing and converting polysulfides and carbon black enhancing the cathode conductivity. Electrochemical analysis of the lean-electrolyte cells shows that the incorporation of LLTO improves cell performance, with enhanced discharge capacity of 715–836 mAh g−1 at C/5–C/10 rates and notable capacity retention after 100 cycles, compared with cathodes without additives or with carbon black. Further investigations demonstrate the superior performance of the cell incorporating LLTO in a LiNO3-free electrolyte, attributable to the promotion of ion transport and polysulfide adsorption by LLTO, resulting in high discharge capacities (846 mAh g−1 at C/10), efficiency (93–99 %), and stability. Overall, this study compares the effects of electronically and ionically conductive additives on cell performance and highlights the effectiveness of the ionically conductive LLTO. The incorporation of such additives offers innovative solutions to the key challenges for the development of high-performance energy-storage devices.

Vinyl-bearing sp2 carbon-conjugated covalent organic framework composites for enhanced electrochemical performance in hydrogen evolution reaction and lithium–sulfur batteries

Vinyl-bearing triazine-functionalized covalent organic frameworks (COFs) have emerged as promising materials for electrocatalysis and energy storage. Guided by density functional theory calculations, a vinyl-enriched COF (VCOF-1) featuring a donor–acceptor structure was synthesized based on the Knoevenagel reaction. Moreover, the VCOF-1@Ru without pyrolysis was obtained through chemical coordination interactions between VCOF-1 and RuCl3, exhibiting enhanced electrocatalytic performance in the hydrogen evolution reaction when exposed to 0.5 M H2SO4. The results demonstrated that the protonation of VCOF-1@Ru enhanced the electrical conductivity and accelerated the generation of H2 on the catalytically active site Ru. Additionally, VCOF-1@CNT with a tubular structure was prepared by uniformly wrapping VCOF-1 onto carbon nanotubes (CNTs) and using it as a cathode for lithium–sulfur batteries by chemically and physically encapsulating S. The enhanced performance of VCOF-1@CNT was attributed to the effective suppression of lithium polysulfide migration. This suppression was achieved through several mechanisms, including the inverse vulcanization of vinyl on VCOF-1@CNT, the enhancement of material conductivity, and the interaction between N in the materials and Li ions. This study demonstrated a strategy for enhancing material performance by precisely modulating the COF structure at the molecular level.

Layered CoMoS3.13@NCNTs with a Rod-Shaped Skeleton as the Cathode of Lithium–Sulfur Batteries

Layered CoMoS_3.13@NCNTs with a Rod-Shaped Skeleton as the Cathode of Lithium–Sulfur Batteries

Perspective of material evolution Induced by sinusoidal reflex charging in lithium-ion batteries

BackgroundLithium-ion batteries are globally prominent and extensively employed alternative energy sources with decisive applications. In depth understanding of influences of various charging and discharging cycles on electrode materials and life span of these batteries is critical as cycle-life and safety of lithium-ion batteries are closely related crystallinity of electrode materials. This study is a detailed investigation endeavor in observing the degree of damage to electrode materials under multiple charging and discharging cycles. Methodology: A constant current-sinusoidal reflex charging method (CC-Sinusoidal) was implemented to charge commercial cathode Lithium cobalt oxide (LiCoO2) electrodes and anode graphite electrodes in comparison to the conventional charging method of constant current-constant voltage (CC-CV). After 100, 300, and 500 cycles of charging and discharging, EIS, SEM, XRD, and Raman spectroscopies were used to compare the degree of electrode damage caused by different charging methods. Significant outcomesThe structure of positive LiCoO2 electrode of the battery was observed to be stable, with no significant change in both the charging methods after 500 cycles. The use of CC-CV charging method had caused severe damages to graphite electrode with generation of solid electrolyte interface (SEI) films. The CC-Sinusoidal charging method had maintained the electrode material in a relatively ideal state.

Natural Microcellulose Fibers as Intercalants of Graphitic Cathodes for High-Performance Lithium–Sulfur Batteries

Natural Microcellulose Fibers as Intercalants of Graphitic Cathodes for High-Performance Lithium–Sulfur Batteries

Enhanced prelithiation performance of Li5FeO4 cathode additive and optimized solid electrolyte interface enabled by Mn substitution

In the pursuit of enhancing the energy density of lithium-ion batteries, cathode prelithiation emerges as a pivotal approach, introducing additional irreversible active lithium ions to augment performance. Li5FeO4 (LFO) stands out as an excellent option, boasting an impressive theoretical specific capacity and the additional advantages of cost-effectiveness in raw materials and low preparation cost. However, the impact of extra lithium incorporations on compositional changes at the electrode-electrolyte interface as well as on cell stability has impeded further researches. Herein, a Mn doping strategy is proposed and predicted by first-principles calculations to synthesize partially Mn-substituted Li5.125Fe0.875Mn0.125O4 (LFMO). And the prelithiation with LFMO improved the interfacial composition of LiFePO4 (LFP) batteries compared to LFO, achieving a charging capacity of 213 mAh∙g−1 in the first cycle at 0.05 C. The subsequent treatment demonstrated superior cycling stability, maintaining a discharge specific capacity as high as 155.3 mAh∙g−1 after 100 cycles at 0.2 C, and exhibiting a higher capacity retention in the full cell. These discoveries could contribute to enhancing the regulation of battery interface during the utilization of LFO, potentially promoting the development of cathode lithium additives.

Uncovering the predictive pathways of lithium and sodium interchange in layered oxides.

Ion exchange is a powerful method to access metastable materials with advanced functionalities for energy storage applications. However, high concentrations and unfavourably large excesses of lithium are always used for synthesizing lithium cathodes from parent sodium material, and the reaction pathways remain elusive. Here, using layered oxides as model materials, we demonstrate that vacancy level and its corresponding lithium preference are critical in determining the accessible and inaccessible ion exchange pathways. Taking advantage of the strong lithium preference at the right vacancy level, we establish predictive compositional and structural evolution at extremely dilute and low excess lithium based on the phase equilibrium between Li0.94CoO2 and Na0.48CoO2. Such phase separation behaviour is general in both surface reaction-limited and diffusion-limited exchange conditions and is accomplished with the charge redistribution on transition metals. Guided by this understanding, we demonstrate the synthesis of NayCoO2 from the parent LixCoO2 and the synthesis of Li0.94CoO2 from NayCoO2 at 1-1,000 Li/Na (molar ratio) with an electrochemical assisted ion exchange method by mitigating the kinetic barriers. Our study opens new opportunities for ion exchange in predictive synthesis and separation applications.

Nickel aerogel @ ultra-thin NiCo-LDH nanosheets integrated freestanding film as a collaborative adsorption and accelerated conversion cathode to improve the rate performance of lithium sulfur batteries

It is a great challenge to develop freestanding ultralight cathodes for lithium–sulfur battery exhibiting good electrochemical performances. Herein, ultrathin porous nickel–cobalt layered double hydroxide (NiCo-LDH) nanosheets were grown on the surface of ultra-light nickel microwire aerogels (NMWAs), and there is capillary action in the gaps formed by the ordered arrangement due to the presence of magnetic filed in the preparation process, which has the advantages of synergistic adsorption and accelerated conversion kinetics of lithium polysulfide. Because of the abundant hydrophilic hydroxyl groups on the surface of NiCo-LDH and the capillary action of NMWAs, the integrated freestanding film cathode sulfur host (NMWAs@NiCo-LDH/S) provides excellent rate performance as well as cycling stability. The film cathode has an ultra-high initial specific capacity of 1238.4 mAh g−1 at 0.1C and an excellent reversible capacity of 805.8 mAh/g at 5.0C. Even after 700 cycles at a high current density of 5.0C, it still provides a reversible capacity of 647.1 mAh g−1 with a capacity decay rate of only 0.018 % per cycle. This work provides a simple and new way for the design of high rate lithium–sulfur battery film cathodes with good cycle stability.

Application metal oxide cathode materials for lithium ion batteries

The popularity of portable electronic devices has boosted the speedy advancement of devices for storing electrical energy. At the same time, the development of electric vehicles urgently requires lithium batteries to have higher power density and performance. The strong points of lithium ion battery are environmental friendliness, also specific capacity of high level. Lithium cathode material is one of the key factors affecting battery performance. The requirements for positive electrode materials are good safety, good service life, and less self-discharge. Among all cathode materials, metal oxide cathode material is the most potential types, which comes from a wide range of sources and has rich production experience. In this paper, four kinds of lithium metal oxide cathode materials including lithium cobaltate, lithium nickelate, lithium manganate and ternary composite oxide cathode material were analyzed, and discussed the performance of lithium metal oxide cathode materials in practical applications, where further pointed out the existing problems of metal oxide cathode materials and put forward several directions for future improvement to improve the performance of lithium ion battery cathode materials in the future development and production process.

Advancements in Addressing Microcrack Formation in Ni–Rich Layered Oxide Cathodes for Lithium–Ion Batteries

AbstractNickel–rich layered oxides of LiNi1–x–yCoxMn(Al)yO2 (where 1–x–y>0.6) are considered promising cathode active materials for lithium‐ion batteries (LIBs) due to their high reversible capacity and energy density. However, the widespread application of NCM(A) is limited by microstructural degradation caused by the anisotropic shrinkage and expansion of primary particles during the H2→H3 phase transition. In this mini–review, we comprehensively discuss the formation of microcracks, subsequent material degradation, and related alleviation strategies in nickel–rich layered NCM(A). Firstly, theories on microcracks′ formation and evolution mechanisms are presented and critically analyzed. Secondly, recent advancements in mitigation strategies to prevent degradation in Ni–rich NCM/NCA are highlighted. These strategies include doping, surface coating, structural optimization, and morphology engineering. Finally, we provide an outlook and perspective to identify promising strategies that may enable the practical application of Ni–rich NCM/NCA in commercial settings.

Preferentially selective recovery of lithium from spent LiCoO2 by sulfation roasting of MnSO4

The selective recovery of valuable metals from spent lithium-ion batteries (LIBs) has engrossed significant scientific attention due to prompting environmental potential and addressing resource scarcity. Hereby, we propose an innovative and economically more environment friendly manganese sulfate roasting water leaching process to selectively recuperate lithium preferentially from spent LiCoO2 batteries. Notably, it is found that manganese sulfate roasting agents can be recirculated thoroughly without SOx emission during the sulfation roasting process. To better understand the conversion mechanism of LiCoO2, the effects of numerous parameters including, roasting time, roasting temperature, and a molar ratio of MnSO4/LiCoO2 during the recovering process were investigated. An exceptional recovery rate of 98.62% with a remarkable lithium selectivity of 99.35% by manganese sulfate leaching was achieved. This work proposes an environmentally friendly and promising strategy to extract lithium selectively from spent lithium cathodes without introducing SOx emission.

Cost effective synthesis of 3-dimensional V4O9: A promising high-capacity lithium cathode

The earthly abundant vanadium exhibits multi-oxidation states and different crystalline structures in their oxide compounds offering unique electrical, opto-electronic, and catalytic properties to be applicable for various applications including energy storage materials. The stable vanadium oxides (V2O5, VO2, V2O3) are mostly studied while metastable oxides such as V4O9 is less explored. The latter possesses a tridimensional (3D)-tunnel defect type structure with different polyhedral wherein VO5 pyramids and VO6 octahedra are connected by corner oxygen atoms from the VO4 tetrahedra with V4+ and V5+ oxidation states, respectively, making it an appealing host candidate for lithium-ions insertion. Herein, we present a cost-effective single pot synthesis of 3D V4O9 nanoparticles using versatile low temperature solvothermal method. The obtained material has been fully characterised in terms of phase identity and crystal structure using x-ray diffraction, Raman spectroscopy and high-resolution-transmission-electron-microscopy while surface composition and valence- and/ oxidation states using x-ray photoelectron spectroscopy followed by investigation of its electrochemical performance against lithium. Upon first discharge, V4O9 could intercalate ∼6 Li+ per formula unit corresponding to highest discharge capacity of 464.5 mA h g−1 and a reversible first Coulombic efficiency of 75.3% between 1.5 – 4.0 V against Li in a half-cell configuration. In the long run, the V4O9 exhibited a reversible capacity of 160.8 mA h g−1 at 100 mA g−1 even after 2000 cycles against lithium rendering it as suitable positive electrode with high capacity and cyclability for lithium-ion battery applications.

Rich-Carbonyl Carbon Catalysis Facilitating the Li2CO3 Decomposition for Cathode Lithium Compensation Agent.

The active lithium loss of lithium-ion batteries can be well addressed by adding a cathode lithium compensation agent. Due to the poor conductivity and electrochemical activity, lithium carbonate (Li2CO3) is not considered as a candidate. Herein, an effective cathode lithium compensation agent, the recrystallized Li2CO3 combined with large specific surface area disordered porous carbon (R-LCO@SPC) is prepared. The screened SPC makes it easier for nano-sized Li2CO3 to adsorb and decompose on carbon substrate, meantime, exposing plenty of catalytic active sites of C═O, which can significantly improve the electrochemical activity and conductivity of Li2CO3, thus greatly reducing the decomposition potential of Li2CO3 (4.0V) and releasing high irreversible capacity (580mAhg-1) compared to the unmodified Li2CO3 (nearly no capacity above 4.6V). Meantime, the Li2CO3 can disappear completely without any by-product after the initial cycle accompanied by partially dissolved in electrolyte, optimizing the composition of SEI. The resultant lithium compensation agent applied to LMFP//graphite full cell exhibits a 19.1% increase in energy density, enhancing the rate and cycling performance, demonstrating great practical applications potential in high energy density lithium-ion batteries.