Performance Of Cathode Materials Research Articles

Surface modification single crystal Li-rich Li1.2Mn0.54Ni0.13Co0.13O2 as high performance cathode materials for Li-ion batteries

To improve electrochemical performance and structure stability, Li3PO4 surface modification and single crystallization are applied for Li1.2Mn0.54Ni0.13Co0.13O2 to improve structural stability and upgrade electrochemical performance. The electrochemical characterization indicates that single crystal cathode material with Li3PO4 surface modification has high cycle stability and superior Li+ diffusion coefficient. Li-ion conductor Li3PO4 can supply diffusion channels for Li+ migration and inhibit phase transition. Coating Li3PO4 on Li-rich cathode materials is an effective method to improve the electrochemical performance and structure stability of the materials.

Microstructure and Electrochemical Performance of Rapidly Sintered LiCoO2 Cathodes

Lithium ion battery technology based upon liquid carbonate electrolytes and intercalation electrodes has achieved widespread commercial success. The batteries power mobile devices like cell phones, laptop computers and cordless power tools. They are used in hybrid and all electric vehicles to reduce greenhouse gas emissions and dependency on limited petrochemical resources. They have been demonstrated to stabilize electric grids at local and national levels under periods of high demand. Even with these remarkable achievements, improvements in energy density are sought in batteries for most applications. Lithium metal batteries are being pursued around the world to meet this need.Rapid, continuous, roll-to-roll sintering of alumina ceramic tapes was recently demonstrated at Corning Incorporated [1]. The process is based on the pioneering work of Ketcham et al [2]. The ceramic tape, because it is thin, is flexible and may be heated, sintered, and cooled back to room temperature in less than one hour without cracking. One application of this technology is for manufacture of thin, <30 µm, solid electrolyte separators. Another is to enable novel, cathode-supported battery architectures. To that end, rapid sintering has been extended to lithium cobaltite (LCO). Continuous sintering and winding of LCO is shown in Fig. 1. The LCO cathode because it is sintered and self-supporting may be used to reduce the proportions of inactive components to dramatically increase energy density. Both composite and dense cathodes can be envisioned.One possible way of creating a solid-state battery with LCO ribbon is to capitalize on the LiPON solid electrolyte originally developed at ORNL for thin-film micro-batteries (TFMB’s) [3, 4]. The materials in TFMB’s have proven track records and attractive performance attributes. The LiPON solid electrolyte in contact with a lithium metal anode is resistant to dendrite formation even at current densities >5 mA/cm²; a claim that cannot be made for lithium garnet and lithium phosphosulfide glass [5, 6].TFMB’s also have tremendous cycling longevity and retain more than 90% of capacity after over 104 charge-discharge cycles [7]. The challenge with the technology is the high cost associated with growth of the cathode by sputtering processes; thicknesses are limited to ~2-3 µm. As a consequence, TFMB’s are a good fit for applications where small size power sources are needed like smart cards, medical implants, RFID tags, and wireless sensing. A thicker, rapidly sintered cathode could address the cost-capacity limitation. The cathode for this architecture could be made in a dense, closed pore form or with 15-25% porosity to host and electrolyte. The later would be expected to offer greater rate performance due to shorter diffusion distances and greater surface area for charge transfer. Energy density of more than 1,500 Wh/L is theoretically achievable.The performance of cathode materials like LCO depends upon synthesis conditions, process history, design and microstructure. We explore the electrochemical attributes of free standing LCO cathodes with thickness of 15 to 80 µm and porosity ranging from closed (dense) to ~25%. Cathodes were tested in 2032 coin cells using Whatman glass fiber as the separator and 1 M LiPF6 in 1:1 EC:DMC. Capacity of the cathodes regardless of microstructure is near the theoretical value. Lithium diffusivity of dense polycrystalline cathodes was characterized by galvanostatic intermittent titration and averages 1.13×10-9 cm²/s over the potential window of 3.0 to 4.3 V. Surface XRD shows the grain texture to be nominally random. Approximately 50% capacity was available at C/2 at a 23 µm thickness. Resistance of porous cathodes decreased with perimeter-to-surface area, and effective resistances below 10 Ωcm² were observed. Cycling endurance of porous sintered cathodes with 2.4 mAh/cm² capacity was evaluated with lithium titanate working electrodes. More than 90% capacity was retained after 1000 cycles between 3.0 and 4.3 V vs Li at 3C rate.[1] C. Kim, et al, “5G mm Wave Patch Antenna on Multi-layered Alumina Ribbon Ceramic Substrates,” IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting, July 2020, pp. 65-66.[2] T.D. Ketcham, et al., US 5,089,455, Feb 18, 1992.[3] J.B. Bates, et al., Solid State Ionics, 53-56 (1992) 647-654.[4] J.B. Bates, et al., U.S. 5,561,004, Oct 10, 1996.[5] F.D. Han, et al., Nat. Energy, (2019) 1-10.[6] J.C. Li, et al., Adv. Energy. Mater., 5 (2015) 1401408.[7] J. Xie, et al., Solid State Ionics, 178 (2008) 362-370. Figure 1

Bifunctional Electrocatalysts Materials for Non-Aqueous Li–Air Batteries

Rechargeable lithium–air batteries (LABs), particularly the nonaqueous form, are demonstrated as the next-generation energy conversion and storage equipment for many applications. The air cathode has been certified as one of the critical aspects to affect the full performance of the LABs. At present, the main challenge for the commercial application of air cathode is to exploit some new cathode catalysts with lower prices, higher efficiency, and better stability. In the last decade, tremendous efforts have been dedicated to developing new structure design and fabrication processes of the cathode materials to promote the full capability of the LABs. The recent research progress of bifunctional cathode catalysts for LABs, including the main improvement strategies and performance of cathode materials, is introduced in this paper. Besides, related technical challenges are analyzed, and possible resolving strategies for the challenges to develop the nonaqueous Li–air battery catalytic cathodes are elaborated on in this review.

Enhancing structural and cycle stability of Prussian blue cathode materials for calcium-ion batteries by introducing divalent Fe

Calcium-ion batteries (CIBs) have been of interest for rechargeable batteries due to their high energy density and fast ion diffusion in liquid electrolyte originated from the divalence and low charge/radius ratio of Ca ion. However, exploring high performance cathode materials for CIBs is very challenging. In this work, divalent Fe ions are introduced into copper hexacyanoferrate (CuHCF) to construct a new Prussian blue cathode material rich of Fe2+ by using K4Fe(CN)6 as the precursor instead of K3Fe(CN)6. The Fe2+ ions at low-spin state can improve the structural stability of CuHCF during Ca ions extraction and insertion processes effectively. It is found that the lattice parameter change of CuHCF is only 0.13 % during charge and discharge, much less than the CuHCF with Fe3+. X-ray absorption spectroscopy indicates that the charge compensation of CuHCF(Fe2+) is mainly contributed by Fe2+/Fe3+ redox couple. The octahedral distortion in CuHCF is also suppressed effectively. As a result, the CuHCF(Fe2+) cathode can deliver a reversible capacity of 54.5 mAh/g at 20 mA g−1 with a high capacity retention of 90.43 % after 1000 cycles.

An extraordinary Na-S battery enabled by a carbon nanosheet host loaded with Fe-accelerator and TiO2-inhibitor

The inexpensive room-temperature sodium-sulfur (RT Na-S) battery has attracted extensive attention due to its various potential application but is still suffering from the low utilization of sulfur, the shuttle effect and the sluggish reaction activity of sodium polysulfides (SPSs). In this work, a TiO2/sulfur/atomic-iron loaded carbon nanosheet cathode is designed for high performance RT Na-S battery. When the atomic iron exists, a much higher electrochemical activity of sulfur was obtained, indicating the atomic iron can accelerate the conversion of SPSs. Furthermore, the TiO2 layer can inhibit the shuttle effect of SPSs and the side-reaction between the intermediates and carbonate electrolyte. As a result, the constructed sulfur cathode exhibits a high reversible capacity (569.9 mAh g−1 with an initial coulombic efficiency of 57.57%) at 0.1 A g−1 and outstanding cycling performance (507 mAh g−1 after 50 cycles). This work provides a new strategy for preparing high performance cathode materials for RT Na-S battery.

The nitrogen-doped carbon coated Na4MnV(PO4)3 as a high electrochemical performance cathode material for sodium-ion batteries

As a promising cathode material for sodium-ion batteries, the NASICON-structured Na4MnV(PO4)3 (NMVP) possesses a high working voltage with two discharge potential plateaus located at ∼3.4 V and 3.6 V from the V4+/V3+ and Mn3+/Mn2+ redox couples, respectively. However, the rate capability and cycling stability of NMVP is unsatisfactory because of the low electronic conductivity and dissolution of manganese. In this work, a series of NMVP@C-xN (x = 10, 20 and 30) was synthesized using a sol-gel method with the generation of a nitrogen-doped carbon on the surface of NMVP particles to reveal the effect of heteroatom-doped carbon coating on improving the electrochemical performance of the cathode material. Among the prepared samples, NMVP@C–20N exhibited a high initial reversible capacity of 103.8 mAh g−1 at 0.1 C and an excellent cycling stability with a capacity retention of 86.1 % after 2000 cycles at 5 C. The excellent performance of the cathode material should be ascribed to the generation of defects and active sites of the nitrogen-doped carbon coating, leading to increased electronic conductivity and diffusion rate of sodium ions.

Covalent organic framework with active C=O/C=N groups for high performance cathode material for lithium‐ion batteries

The large-scale applications of energy storage system via lithium-ion batteries (LIBs) put forward demands for high capacity, high safety, and low cost of materials. Covalent organic polymers have attracted extensive attention because of their high capacity, flexible structural design, high safety, abundance, and low cost. Here, 2,3,5,6-tetraamino-p-benzoquinone and hexaketocyclohexane octahydrate were chosen as monomers to construct the covalent organic framework (TH-COF) cathode materials with active C=O and C=N groups. The TH-COF was further composed with reduced graphene oxide (rGO) and the prepared TH-COF/rGO cathode provided a capacity of 135 mAh g−1 after 600 cycles at 1 C current density. In addition, after 100 cycles, the cathode delivered capacities of 118 and 73 mAh g−1 at the high current densities of 5 C and 20 C, respectively, displaying superior rate performances. The TH-COF/rGO electrode exhibited high capacity and stability, making it a promising cathode material for the next generation LIBs.

Carbon-Based Modification Materials for Lithium-ion Battery Cathodes: Advances and Perspectives.

Lithium-ion batteries (LIBs) have attracted great attention as an advanced power source and energy-storage device for years due to their high energy densities. With rapid growing demands for large reversible capacity, high safety, and long-period stability of LIBs, more explorations have been focused on the development of high-performance cathode materials in recent decades. Carbon-based materials are one of the most promising cathode modification materials for LIBs due to their high electrical conductivity, large surface area, and structural mechanical stability. This feature review systematically outlines the significant advances of carbon-based materials for LIBs. The commonly used synthetic methods and recent research advances of cathode materials with carbon coatings are first represented. Then, the recent achievements and challenges of carbon-based materials in LiCoO2, LiNixCoyAl1-x-yO2, and LiFePO4 cathode materials are summarized. In addition, the influence of different carbon-based nanostructures, including CNT-based networks and graphene-based architectures, on the performance of cathode materials is also discussed. Finally, we summarize the challenges and perspectives of carbon-based materials on the cathode material design for LIBs.

Reinforced structural stability of Li-rich Mn-based cathodes by constructing multifunctional heterostructure using Nb-based MXenes

Lithium rich manganese based materials (LMR) have promised the likeliestcandidate for next generation lithium-ion battery cathodes owing to its high energy density and low materials cost. However, severe capacity decline and voltage decay hinder their practical application, which is closely concerned with the structure degradation and irreversible oxygen release. Herein, a simple strategy to reinforce the structural stability of LMR materials by constructing heterostructure with Nb-based MXenes (Nb2CTx/Nb4C3Tx) is proposed. A small amount of spinel phase and pseudo-bonding between Nb and O ions as well as extra oxygen vacancies can be induced by the MXenes addition in LMR, effectively inactivating the surface oxygen and suppressing the structure distortion. In addition, MXene can also alleviate the volume change during cycling process and provide additional transport channels for electrons. The ably designed 3 wt% LMR/Nb2CTx cathode presented high initial Coulombic efficiency of 85.6% at 0.1C (vs. 77.4% for the pristine material) and excellent cycling performance with a capacity retention of 83.8% after 200 cycles at 0.5C (vs. 66.6% for the pristine material). This work sheds some light on stabilizing the structure of lithium-rich manganese materials and provides a new idea for the design of other high performance cathode materials.

Porous Spinel Magnesium Manganese Oxide/Multiwalled Carbon Nanotubes Composite Synthesized by Electrochemical Conversion as High-Performance Cathode for Aqueous Magnesium Ion Battery

Aqueous magnesium ion batteries (AMIBs) have attracted great interest due to the low manufacture cost and eco-friendliness, but the lack of suitable cathodes with good electrochemical performance obstructs their development. Here, a composite of spinel magnesium manganese oxide (MgMn2O4) and multiwalled carbon nanotubes (MWCNTs) with a porous structure is synthesized by electrochemical conversion method and used as the cathode for the AMIB, which improves the inherent low conductivity for MgMn2O4 and enhanced its specific capacity. The electrochemical conversion method helps preserve the surface integrity and structure stability of the electrode, and the MWCNTs network provides the pathway of Mg ion migration among the MgMn2O4 particles. The obtained MgMn2O4/MWCNTs displays a discharge capacity of 322.3 mAh g−1 at 50 mA g−1, and the capacity retention is 81.8% after 2000 iterations at 1000 mA g−1. Further, the MgMn2O4/MWCNTs//VO2 system is assembled, which displays a capacity retention rate of near 100%. The electrochemical mechanism of Mg ion insertion/extraction is investigated though the ex situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements. This paper extends synthesis method of the high performance cathode material for AIMB system.

Design guidelines for secondary lithium-ion battery electrodes to overcome performance limitations of recycled cathode materials

Today the ever-growing demand of lithium-ion batteries for electric vehicles is posing a terrible burden on materials availability. In particular, high performance cathode materials, such as LiNixMnyCozO2 (NMC), are becoming increasingly critical, thus requiring recycling processes to maximise their reutilisation. Recyclers are moving towards closed loop solutions, such as co-precipitation and direct recycling methods, which however can provide recycled materials with decreased electrochemical and transport properties compared to virgin ones. This work uses numerical modelling to provide design guidelines to overcome performance losses of recycled cathode materials. The model and its parametrisation are validated against experimental data of a virgin NMC cell. An impact assessment on battery performance is carried out showing that a plausible decrease in theoretical volumetric capacity and Li diffusivity in cathode active material leads to both lower accessible capacity during discharge and inferior performance during charge. Nevertheless, a design analysis indicates that recycling degradation can be effectively overcome by simple compensatory measures, such as a limited increase in electrode thicknesses and/or minor decrease in active material diameter, providing similar roundtrip efficiency, energy density, safe thermal operation and performance of the original cell made with virgin materials.

N/Br co-doped C coating Zn2VO4 as excellent electrochemical performance cathode material for aqueous zinc ion batteries

Rechargeable aqueous zinc-ion batteries are considered promising candidates for large-scale energy storage due to its low cost and high safety. However, the strong electrostatic forces between the Zn2+ ions and the host material, low conductivity and slow ion diffusion kinetics of cathode materials hinder its development. Zn2VO4 coating with N and Br co-doped C was successfully prepared using CTAB as N/Br co-doped C source. The coating of N/Br co-doped C improves the electrical conductivity and electrochemical activity of the material. As cathode material for ZIBs, it displays an initial discharge capacity of 181 mAh g−1 at 1 A g−1, and a high capacity of 120 mAh g−1 with 0.8 % capacity delay rate over 5000 cycles at high current density of 5 A g−1. Meanwhile, the material electrode displays fast ionic diffusion as well as excellent charge transfer kinetics which are favorable for fast energy storage and conversion.

Facilitating Mg2+ diffusion in high potential LixV2(PO4)3 cathode material with a co-insertion strategy for rechargeable Mg-ion batteries

Rechargeable Mg-ion batteries offer high energy density and good safety. However, the lack of cathode materials with high operating potential and considerable capacity is a great challenge for their practical applications. This is limited by the sluggish diffusion of multivalent Mg 2+ cations in solid lattices. Here, we propose a co-insertion strategy to facilitate cation diffusions and present a polyanion cathode of Li 3 V 2 (PO 4 ) 3 to provide high redox potential. The initial charge of the material is associated with the extraction of two Li + cations, which are co-inserted with Mg 2+ from the 0.5 m Mg(ClO 4 ) 2 /PC electrolyte during the following electrochemical processes. The cation diffusion coefficients are largely enhanced in comparison to the electrode without Li + co-insertion, and higher capacity is obtained. At room temperature, the Li 3 V 2 (PO 4 ) 3 electrode delivers 124 mAh g −1 capacity at 100 mA g −1 with discharge plateaus at 0.46 V and −0.44 V vs. Ag/Ag + . A capacity retention of 80% is realized after 300 cycles at 500 mA g −1 . A rocking-chair Mg-ion full cell coupling the Li 3 V 2 (PO 4 ) 3 cathode with an anthraquinone anode achieves 41 mAh g −1 capacity (based on the mass of both electrodes). The work demonstrates a promising pathway for the design of high performance cathode materials for Mg-ion batteries. • A high potential polyanion cathode of Li 3 V 2 (PO 4 ) 3 is proposed for Mg-ion batteries. • A co-insertion strategy is revealed to enhance cation diffusion in solid lattices. • The Li 3 V 2 (PO 4 ) 3 electrode delivers 124 mAh g −1 capacity at 100 mA g −1 . • High discharge potentials of 0.46 V and −0.44 V vs. Ag/Ag + are achieved. • A capacity retention of 80% is realized over 300 cycles with 99.3% CE.

Mn-doped Na4Fe3(PO4)2(P2O7) facilitating Na+ migration at low temperature as a high performance cathode material of sodium ion batteries

Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 (NFPP) is known as a cathode material with great potential for sodium ion batteries (SIBs) due to its thermodynamic stability, considerable theoretical capacity and small volume change. However, its inherent poor conductivity leads to low discharge capacity and poor cycle stability, which greatly limits its widespread and practical application. In this work, a Mn 2+ doped NFPP together with the graphene modification, is proposed. It is found that the optimal Na 4 Fe 2.7 Mn 0.3 (PO 4 ) 2 P 2 O 7 /rGO(Mn0.3-NFPP/rGO) can provide an initial discharge capacity of 131.5 mAh g −1 at 0.1C, (1C = 129mAh g −1 ) also an excellent rate performance (70.2 mAh g −1 at 50C) and good long cycle stability (97.2% capacity retention after 2000 cycles at 10C) can be obtained. Impressively, the as-prepared Mn0.3-NFPP/rGO also shows excellent low-temperature performance, at −20 °C, it demonstrates a discharge capacity of 85.3 mAh g −1 at 0.2C and good rate performance. Density functional theory (DFT) calculation shows that Mn 2+ doping reduces the Na + migration energy barrier, and also narrows the bandgap of the NFPP lattice, which is beneficial to improve the Na + diffusion kinetics and conductivity. In addition, the doping of Mn 2+ can further help to improve its structural stability during the long cycling process. • Mn-doped Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) together with graphene modification is proposed. • Mn 2+ doping reduces the Na + migration energy barrier. • Mn 2+ doping narrows the bandgap of Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ). • The Na + migration is facilitated by Mn 2+ doping, particularly at low temperature.

Manipulating Stable Layered P2-Type Cathode via a Co-Substitution Strategy for High Performance Sodium Ion Batteries.

Mn-based layered transition metal oxides (TMOs) are promising cathodes for sodium ion batteries (SIBs) due to their eco-friendly character and abundant natural reserves. However, the complex phase changes and structural instability of the Mn-based layered TMO cathodes during electrochemical process are major hindrances to meet the commercial application. Cation substitution is an effective way to stabilize the structure and accelerate the Na+ kinetics of cathode materials. Herein, an intriguing layered P2-type Mn-based Na0.7 Li0.06 Zn0.06 Ni0.21 Mn0.67 O2 material is reported by substitution of Li and Zn for partial Ni. The occupation of inert elements on Ni sites could well maintain the crystal structure, giving rise to a prominent cycle life and improved electrochemical kinetics. The as-prepared electrode presents an initial discharge capacity of 131.8mA h g-1 at 20mA g-1 and preserves 91.9% capacity after 100 cycles, accompanied with enexcellent rate performance (108mA h g-1 at 500mA g-1 ). Furthermore, the single-phase reaction mechanism during the sodiation/desodiation process is verified by in situ X-ray diffraction. Additionally, theory computations prove the decreased migration energy barriers and enhanced Na+ kinetics ulteriorly. This dual-doping strategy inspires an effective way to produce high performance cathode materials for SIBs.

N-Doped Carbon Layer Modified Na3v2(Po4)3 as a High- Performance Cathode Material for Sodium Ion Batteries

N-Doped Carbon Layer Modified Na3v2(Po4)3 as a High- Performance Cathode Material for Sodium Ion Batteries

N-Doped Carbon Layer Modified Na3v2(Po4)3 as a High- Performance Cathode Material for Sodium Ion Batteries

N-Doped Carbon Layer Modified Na3v2(Po4)3 as a High- Performance Cathode Material for Sodium Ion Batteries

Surface Modification Single Crystal Li-Rich Li1.2mn0.54ni0.13co0.13o2 as High Performance Cathode Materials for Li-Ion Batteries

Surface Modification Single Crystal Li-Rich Li1.2mn0.54ni0.13co0.13o2 as High Performance Cathode Materials for Li-Ion Batteries

N-Doped Carbon Layer Modified Na3v2(Po4)3 as a High- Performance Cathode Material for Sodium Ion Batteries

N-Doped Carbon Layer Modified Na3v2(Po4)3 as a High- Performance Cathode Material for Sodium Ion Batteries

Three-dimensional ordered hierarchically porous carbon materials for high performance Li-Se battery

Developing host materials with high specific surface area, good electron conductivity, and fast ion transportation channel is critical for high performance lithium-selenium (Li-Se) batteries. Herein, a series of three dimensional ordered hierarchically porous carbon (3D OHPC) materials with micro/meso/macropores are designed and synthesized for Li-Se battery. The porous structure is tuned by following the concept of the generalized Murray's law to facilitate the mass diffusion and reduce ion transport resistance. The optimized 3D Se/OHPC cathode exhibits a very high 2nd discharge capacity of 651 mAh/g and retains 361 mAh/g after 200 cycles at 0.2 C. Even at a high current rate of 5 C, the battery still shows a discharge capacity as high as 155 mAh/g. The improved electrochemical performance is attributed to the synergy effect of the interconnected and well-designed micro, meso and macroporosity while shortened ions diffusion pathways of such Murray materials accelerate its ionic and electronic conductivities leading to the enhanced electrochemical reaction. The diffusivity coefficient in Se/OHPC can reach a very high value of 1.3 × 10−11 cm2/s, much higher than those in single pore size carbon hosts. Their effective volume expansion accommodation capability and reduced dissolution of polyselenides ensure the high stability of the battery. This work, for the first time, established the clear relationship between textural properties of cathode materials and their performance and demonstrates that the concept of the generalized Murray’s law can be used as efficient guidance for the rational design and synthesis of advanced hierarchically porous materials and the great potential of 3D OHPC materials as a practical high performance cathode material for Li-Se batteries.