Kind Of Cathode Material Research Articles

Highly-pseudocapacitive origin and design principles of MoS2 for high-performance aqueous zinc-ion storage

Pseudocapacitive storage of Zn2+ in nanostructured molybdenum disulfide (MoS2) is expected to break through the limitations of sulfide in monovalent or multivalent ions storage; however, the deficiency of theoretical guidance and experimental strategies that enable rational design of MoS2 as a kind of cathode material towards aqueous zinc-ion batteries. Herein, we firstly establish guiding theory in order to design pseudocapacitive MoS2-based cathode in the light of the first-principles calculation, and then propose a simple and effective one-pot template-free solvothermal method to synthesize 1T phase-dominated MoS2 cathode with low crystallinity. Through this method, MoS2 cathode delivers an exceptional reversible capacity of 233 mAhg−1 at 0.05 A g−1, especially at 0.1 A g−1, the stability can achieve >150 cycles, and maintains 84 % capacity retention after 2100 cycles at 5 A g−1. Experimental and theoretical analysis show that such extraordinary pseudocapacitive contribution determines by the synergistic effects in the activated and stable metallic phase, abundant lattice defects and larger interlayer spacing in the rag-like MoS2 cathode. The revealed origin of highly pseudocapacitive Zn2+ storage and design principle for MoS2-based cathode facilitate the design of a variety of efficient cathodes.

Earth‐Abundant Fe‐Mn‐Based Compound Cathodes for Sodium‐Ion Batteries: Challenges and Progress

AbstractSodium‐ion batteries (SIBs) with high energy/power density and low‐cost characteristics are deemed to be one of the best replacements to lithium‐ion batteries for utilizing in large‐scale electric energy storage (EES) devices. Fe‐Mn‐based cathode materials take the leading position in realizing high‐performance SIBs because of their high capacity, environment‐friendly, earth abundant, and low‐cost features, exhibiting huge commercial potential. However, the energy density and cyclic stability are still limited so far, considering the increasing demands for practical applications. In this review, aiming to better understanding the research level and currently existed sore points, the research progress is overviewed for several types of Fe‐Mn‐based cathode materials, including layered oxides, polyanionic compounds and Prussian blue analogues, and refine the electrochemical storage mechanism and structure–performance relationship. Finally, the representative electrochemical performances of these three kinds of cathode materials is summarized, compare the advantages and disadvantages of various materials, point out the existing key scientific problems of these materials, and propose the direction of development in near future. This review makes a thoroughly understanding for Fe‐Mn‐based cathode materials, providing new guidance for future research on SIBs toward real‐world applications.

Introduction of LFP and Ternary Cathode Materials of Lithium Battery

In recent years, with rapid development of mobile devices and electric vehicles, lithium-ion battery as an efficient and clean battery technology has attracted wide attention. Cathode material of Li ion batteries (LIBs) is the core part that determines the battery performance. This paper aims to review the research status and latest progress of cathode materials for Li ion batteries, analyze their advantages and disadvantages, and discuss their application prospects in batteries. The review includes two kinds of cathode materials which are widely used and have the best performance in commercial uses for now: lithium iron phosphate (LFP) cathode material and ternary cathode material. The structure, properties, synthesis and modification methods are analyzed and summarized. Based on the analysis of the two materials respectively, the influence factors and countermeasures on the capacity, cycling life and safety of cathode materials for LIBs are emphatically discussed, and the future development is prospected, too.

Sandwich-like MXene bridged heterostructure electrode enables anti-aggregation and superior storage for aqueous zinc-ion batteries

Severe aggregation and sluggish reaction kinetics are the main research challenges that impair the storage performance of cathode materials for aqueous zinc-ion batteries. In this work, we report the concept of sandwich-like Ti3C2Tx MXene-bridged VO2 heterostructure (VO2/Ti3C2Tx) design to simultaneously relieve the self-aggregation and boost the interfacial storage kinetics. When acting as cathode material, such VO2/Ti3C2Tx electrode can deliver a high specific capacity 415 mAh g−1 at 0.1 A g−1 after 110 cycles, as well as 338 mAh g−1 at 1 A g−1 after 300 cycles, much higher than that of the pure VO2 case. Moreover, such electrode also exhibits remarkably rate capability and cyclic stability, which can retain a specific capacity of 170 mAh g−1 at the high current density of 5 A g−1 after 1500 cycles. The superior storage performance should be mainly benefited from the mixed-dimensional heterogeneous engineering. In addition, the evolution of crystal structure and valence state of electrode upon cycling were investigated, thus a storage mechanism can be revealed. That is, single VO2 phase would be transformed into the VO2 and ZnxV2O5·nH2O mixed phase, with a highly reversible H+/Zn2+ insertion/extraction behavior. Such strategy proposed in this work can be also applied for other kinds of cathode materials and promoting the development of aqueous zinc-ion batteries.

Applicability of the reduction smelting recycling process to different types of spent lithium-ion batteries cathode materials

The high-temperature smelting process based on pyrometallurgy is influential in the field of recycling spent lithium-ion batteries (LIBs) on an industrial scale. However, there are a variety of cathode materials for spent LIBs. The applicability of the high-temperature smelting process to different kinds of cathode materials has not been reported. In this work, the applicability of the reduction smelting process to four different cathode materials is studied. The phase transition, distribution and existence of target elements and the characteristics of the smelting products when different cathode materials are used as raw materials are systematically discussed. The results show that the reduction smelting process can recover the four different cathode materials (LiCoO2, LiFePO4, LiMn2O4, LiNi0.8Co0.1Mn0.1O2) of spent LIBs. The reduction smelting process is also suitable for complex feedstocks containing the four cathode materials. The target elements Co, Cu, Ni, Fe and P are transferred to the alloy. The target elements Li and Mn volatilize into the gas phase. In addition, the future application of the reduction smelting process on an industrial scale is discussed and proposed. This study reveals the excellent applicability of the reduction smelting process to different LIB cathode materials and provides support for the development of a high-temperature smelting process based on pyrometallurgy.

Research Progress of Cathode Materials for Graphene-based Fuel Cells

Graphite is the most widely used cathode material for commercial lithium-ion batteries at present, and the increasing market demand puts forward higher requirements for lithium storage performance of graphite cathode materials. Graphene is a kind of cathode material with great development potential, and its lithium storage performance is influenced by many factors such as structural characteristics, oxygen-containing functional groups and impurity atoms, which leads to complex lithium storage behavior and mechanism. When the polymer with lithium storage activity is compounded with graphene as cathode material, the lithium storage performance is affected by the reversibility of polymer redox and the composite structure. In this article, the working principle of Li-lon and the lithium intercalation mechanism of graphite are introduced, and the research status and progress of graphite cathode materials in surface modification and structural regulation in recent years are emphatically reviewed.

Effect of Zn2+ doping on thermal, structural, morphological, functional group, and electrochemical properties of layered LiNi0.8Co0.1Mn0.1O2 cathode material

The sol–gel method was used to synthesize Zn2+ doped LiNi0.8−xZnxCo0.1Mn0.1O2 (0 ≤ x ≤ 0.05) cathode materials with crystallite sizes ranging from 20.36 to 56.25 nm. The thermal stability of all cathodes were characterized by using thermogravimetric analysis (TGA) and quantity of heat needed is calculated by differential thermal analysis (DTA). Their structural, morphological and functional group analysis by XRD, FE-SEM, and FT-IR spectroscopy respectively. The electrochemical properties of two selected cathodes were also investigated via constant voltage, galvanostatic charge/discharge testing, and electrochemical impedance spectroscopy. The TGA/DTA analysis identified the reaction, weight loss, and phase transformation regions of the precursors. The XRD analysis revealed that all the synthesized cathodes possessed a rhombohedra-hexagonal system with a layered crystalline phase (R3̄m space group). The formation of layered-type structures in all cathodes was also revealed by FT-IR analysis. The content of Zn2+ ions in LiNi0.8−xZnxCo0.1Mn0.1O2 had a significant impact on the structural parameters, such as lattice constants, cell volume, and crystallite size of LiNi0.8Co0.1Mn0.1O2. The level of cation mixing and layered structure of all samples were found to be 1.22–1.38 and 4.9827–5.0195, respectively, indicating that all samples possessed minimal cation mixing and a well-defined layered structure. Such behaviors are important for obtaining improved cyclic performance from these kinds of cathode materials. Agglomerated and porous structure morphology with a grain size from 200 to 320 nm was observed via FE-SEM. The initial discharge capabilities for the LiNi0.8Co0.1Mn0.1O2 and LiNi0.77Zn0.03Co0.1Mn0.1O2 cathodes were found to be 214.84 and 233.57 mAh g−1, respectively, at a 0.1 C current rate between 3.0 and 4.6 V. This revealed that the discharge capacity of the pristine LiNi0.8Co0.1Mn0.1O2 cathode was significantly increased by doping Zn2+ with an x = 0.03 content, which is higher than the previously reported LiNi0.33Co0.33Mn0.33O2 cathode.

State of Charge Estimation of Lithium-Ion Battery for Electric Vehicles under Extreme Operating Temperatures Based on an Adaptive Temporal Convolutional Network

The accurate estimation of state of charge (SOC) under various conditions is critical to the research and application of batteries, especially at extreme temperatures. However, few studies have examined the SOC estimation performance of estimation algorithms for several types of batteries under such conditions. In this study, a new method was derived for SOC estimation and a series of experiments were conducted covering five types of lithium-ion batteries with three kinds of cathode materials (i.e., LiFePO4, Li(Ni0.5Co0.2Mn0.3)O2, and LiCoO2), three test temperatures, and four real driving cycles to verify the proposed method. The test temperatures for battery operation ranges from −20 to 60 °C. Then, an adaptive machine learning (ML) framework based on the deep temporal convolutional network (TCN) and Coulomb counting method was proposed, and the structure of the estimation model was designed through the Taguchi method. The accuracy and generalizability of the proposed method were evaluated by calculating the estimation errors and their standard deviations (SDs), its average errors showed a decline of at least 49.66%, and its SDs showed a decline of at least 45.88% when compared to four popular ML methods. These traditional ML methods performed poor accuracy and stability at extreme temperatures (−20 and 60 °C) when compared to 25 °C, while the proposed adaptive method exhibited stable and high performances at different temperatures.

Research Status of Ni-rich Ternary Cathode Materials for Lithium Ion Batteries

Ternary cathode material LiNixCoyMn1-x-yO2(NCM) has been widely studied as a kind of cathode material with high voltage, high theoretical capacity, good cycling performance and high thermal stability, which is one of the most popular cathode materials for lithium ion battery. Nickle-rich NCM (⩾0.5) can meet the market demand for high-specific capacity power batteries due to its high nickel content and large charge-discharge capacity, But the safety and thermal stability are poor. Therefore, this paper mainly studies how to obtain Ni-rich NCM with high specific capacity and good thermal stability from three aspects of precursor preparation, surface coating and doping.

Bulk / Surface Stabilized Tungsten Doped Ni-Rich Li[NixCoyMn(1-x-y)]O2 Layered Cathode Material for High-Energy-Density Lithium-Ion Batteries

With electric vehicles (EVs) industry growing at an alarming rate, many kinds of cathode materials were developed so far to satisfy increasing needs for more energy density and cycling lifespan.[1] Regarding structural stability, nothing but layered transition-metal (TM) oxide cathode materials especially Li[NixCoyMn(1-x-y)]O2 and Li[NixCoyAl(1-x-y)]O2 (0.5 < x < 0.8) so called NCM and NCA are used as a practical lithium ion batteries (LIBs) cathodes for EV applications.[2] Especially, NCM and NCA with even higher nickel contents (x > 0.8) are getting much attention in these days. At the end of Ni-rich cathode material lies pure LiNiO2 (LNO), however, the intrinsic structural instability, poor thermal property and complexity on synthesis highly limits its practical application.[3] By referring to J.-H. Kim et al., in order to increase the energy density of Ni-rich cathode material, it may be advantageous to raise the potential rather than increase the nickel contents further.[4] In this study, a series of tungsten (0.5 and 1.0 mol%) were incorporated in Ni-rich layered Li[Ni0.90Co0.05Mn0.05]O2 cathode material to investigate the stabilization role of tungsten especially on higher voltage and thermally aged condition. In situ X-ray diffraction analysis linked with cross-sectional visual imaging were done to demonstrate the effect of tungsten on bulk lattice stabilization. Surface protectivity at upper potential of disordered spinel-like phases which come from tungsten doping was proved through impedance spectroscopy and post-mortem TEM analysis. References S.-T. Myung, F. Maglia, K.-J. Park, C. S. Yoon, P. Lamp, S.-J. Kim, Y.-K. Sun, ACS Energy Lett. 2017, 2, 196.Teslar Motors, http://www.teslamotors.com/ (accessed: December 2017).C. S. Yoon, D.-W. Jun, S.-T. Myung, Y.-K. Sun, ACS Energy Lett. 2017, 2, 1150.J.-H. Kim, K.-J. Park, S. J. Kim, C. S. Yoon, Y.-K. Sun, J. Mater. Chem. A, 2019, 7, 2694

Comparative studies of zirconium doping and coating on LiNi0.6Co0.2Mn0.2O2 cathode material at elevated temperatures

Layered LiNi0.6Co0.2Mn0.2O2 (NMC) is a promising cathode material for lithium-ion batteries, but structural instability and rapid capacity decay at high voltages and elevated temperatures preclude its large-scale commercialization. Lattice doping and surface coating can address these problems, but the different mechanisms between them are still unclear. Herein, two kinds of cathode materials (Zr-doped NMC and ZrO2-coated NMC) are synthesized and the effects of doping and coating on the structural stability and electrochemical performance of NMC are systematically investigated. Zr-doped NMC exhibits superior electrochemical performance with 98% capacity retention after 50 cycles between 3.0 and 4.5 V at 55 °C. In contrast, pristine and ZrO2-coated NMC suffer continual capacity decay during cycling. Ex situ analyses reveal that the performance improvement originates from the structure stabilizing effects of Zr doping and the robust interfacial film on the cathode surface during cycling. The results suggest that lattice doping is a key factor in obtaining excellent cycling performance at high temperatures. This study provides further insight into the different effects of Zr doping/coating and can be extended to investigate other cathode materials.

Synthesis of disk-like LiNi1/3Co1/3Mn1/3O2nanoplates with exposed (001) planes and their enhanced rate performance in a lithium ion battery

With the addition of span 85, disk-like LiNi1/3Co1/3Mn1/3O2 nanoplates with exposed (001) planes were synthesized using a simple Pechini method. The diameter of the disk-like LiNi1/3Co1/3Mn1/3O2 nanoplates was approximately 50 nm while the thickness was around 3 nm. This result showed that the mixture of liquid surfactants played a key role in the change of morphology of the LiNi1/3Co1/3Mn1/3O2 nanoplates. This kind of cathode material, which was applied in a lithium ion battery, achieved a high specific capacity of 165 mA h g−1 at 2C after 200 cycles, together with a capacity retention ratio of 98.2%.

Selective Recovery of Lithium from Cathode Materials of Spent Lithium Ion Battery

Selective recovery of lithium from four kinds of cathode materials, manganese-type, cobalt-type, nickel-type, and ternary-type, of spent lithium ion battery was investigated. In all cathode materials, leaching of lithium was improved by adding sodium persulfate (Na2S2O8) as an oxidant in the leaching solution, while the leaching of other metal ions (manganese, cobalt, and nickel) was significantly suppressed. Optimum leaching conditions, such as pH, temperature, amount of Na2S2O8, and solid/liquid ratio, for the selective leaching of lithium were determined for all cathode materials. Recovery of lithium from the leachate as lithium carbonate (Li2CO3) was then successfully achieved by adding sodium carbonate (Na2CO3) to the leachate. Optimum recovery conditions, such as pH, temperature, and amount of Na2CO3, for the recovery of lithium as Li2CO3 were determined for all cases. Purification of Li2CO3 was achieved by lixiviation in all systems, with purities of the Li2CO3 higher than 99.4%, which is almost satisfactory for the battery-grade purity of lithium.

ChemInform Abstract: Recent Progress in Hybrid Cathode Materials for Lithium Ion Batteries

AbstractReview: 129 refs.

Carbon incorporation effects and reaction mechanism of FeOCl cathode materials for chloride ion batteries.

Metal oxychlorides are proved to be new cathode materials for chloride ion batteries. However, this kind of cathode materials is still in a very early stage of research and development. The obtained reversible capacity is low and the electrochemical reaction mechanism concerning chloride ion transfer is not clear. Herein, we report FeOCl/carbon composites prepared by mechanical milling of the as-prepared FeOCl with carbon nanotube, carbon black or graphene nanoplatelets as cathode materials for chloride ion batteries. The electrochemical performance of the FeOCl electrode is evidently improved by the incorporation of graphene into the cathode. FeOCl/graphene cathode shows a high reversible capacity of 184 mAh g−1 based on the phase transformation between FeOCl and FeO. Two stages of this phase transformation are observed for the FeOCl cathode. New insight into the reaction mechanism of chloride ion dissociation of FeOCl is investigated by DFT + U + D2 calculations.

Improvement of Lighting Uniformity and Phosphor Life in Field Emission Lamps Using Carbon Nanocoils

The lighting performances and phosphor degradation in field emission lamps (FELs) with two different kinds of cathode materials—multiwalled carbon nanotubes (MWCNTs) and carbon nanocoils (CNCs)—were compared. The MWCNTs and CNCs were selectively synthesized on 304 stainless steel wire substrates dip‐coated with nanosized Pd catalysts by controlling the growth temperature in thermal chemical vapor deposition, and the film uniformity can be optimized by adjusting the growth time. FELs were successfully fabricated by assembling these cathode filaments with a glass bulb‐type anode. The FEL with the CNC cathode showed much higher lighting uniformity and light‐spot density and a lower current at the same voltage than that with the MWCNT cathode filament, and its best luminous efficiency was as high as 75 lm/W at 8 kV. We also found that, for P22, the phosphor degradation can be effectively suppressed by replacing MWCNTs with CNCs in the cathode, due to the much larger total bright spot area and hence much lower current density loading on the anode.

A novel monoclinic manganite/multi-walled carbon nanotubes composite as a cathode material of lithium-air batteries

A novel composite of monoclinic manganite/multi-walled carbon nanotubes (γ-MnOOH/MWCNTs) composite as a cathode material of lithium-air batteries was successfully synthesized by a simple one-step hydrothermal method. Owing to the unique three-dimensional network of γ-MnOOH embedded in the porous structure of MWCNTs, the γ-MnOOH/MWCNTs composite could have an advantage of high electrocatalytic activities over those of two other kinds of cathode materials (MWCNTs and γ-MnOOH/MWCNTs mixture). The results of charge-discharge tests showed that the γ-MnOOH/MWCNTs composite as a cathode material of lithium-air batteries could effectively enhance the catalytic activity for the oxygen evolution reduction (OER) process. The lithium-air battery based on γ-MnOOH/MWCNTs composite exhibits low charge potential and high discharge capacity.

Real-time temperature measurement with fiber Bragg sensors in lithium batteries for safety usage

In this work, fiber Bragg grating (FBG) sensors are integrated in lithium batteries to measure temperature variations. In situ calibration of the FBG sensors against a co-located thermocouple shows a linear response. The thermal behavior of lithium batteries is real-time recorded by FBG sensors, during the batteries operation under normal and abnormal conditions. In spite of the small cathode mass and a low current, temperature variations of 0.1°C are detected. The sensors also exhibit good thermal response to dynamic loading when compared with the thermocouple. The thermal stabilities of four kinds of cathode materials are estimated using FBGs testing results.

Progression of the silicate cathode materials used in lithium ion batteries

Abstract Poly anionic silicate materials, which demonstrate a high theoretical capacity, high security, environmental friendliness and low-cost, are considered one of the most promising candidates for use as cathode materials in the next generation of lithium-ion batteries. This paper summarizes the structure and performance characteristics of these materials. The effects of different synthesis methods and calcination temperature on the properties of these materials are reviewed. Materials that demonstrate low conductivity, poor stability, cationic disorder or other drawbacks, and the use of various modification techniques, such as carbon-coating or compositing, elemental doping and combination with mesoporous materials, are evaluated as well. In addition, further research topics and the possibility of using these kinds of cathode materials in lithium-ion batteries are discussed.

One-Step Synthesis of Asphalt Based Li3V2(PO4)3/C Nanocomposites as Cathode Materials for Lithium-Ion Batteries

A new kind of cathode materials, Li3V2(PO4)3/C nanocomposites, has been prepared via one-step solid-state reaction using ultra low-cost asphalt as both reduction agents and carbon sources. The asphalt is contained 60.37% of fixed carbon and 0.18% of other impurity.It is purchased from Zhen jiang Xin Guang Metallurgical Subsidiary Material Plant. Structural analysis shows that the obtained Li3V2(PO4)3/C nanocomposites contain abundant Li3V2(PO4)3 nanorods and micro/nano particles encapsulate with carbon shells. The Li3V2(PO4)3/C nanocomposites achieve enhanced dischargeability, reversibility, and cycleability. Electrochemical tests show that the Li3V2(PO4)3/C nanocomposite has initial discharge capacities of 170 mAhg-1 at 0.1C in the voltage range of 3.0 to 4.8 V. The improved electrochemical properties of the Li3V2(PO4)3/C nanocomposites are attributed to the presence of Li3V2(PO4)3/C nanorods and the electronically conductive carbon shell. This one-step solid state reaction using low-cost asphalt as carbon sources is feasible for the preparation of the Li3V2(PO4)3/C nanocomposites which can offer favorable properties for commercial applications.