Cobalt-free Cathode Materials Research Articles

Surface modification of rare earth elements to enhance the electrochemical stability of Ni-rich Co-free cathodes

The Ni-rich Co-free cathode materials are considered the most optimistic choice for the long-term economic development of lithium-ion batteries (LIBs) due to the limited supply and high prices of cobalt. In this study, a uniform samarium oxide (Sm2O3) layer was coated on the surface of LiNi0.8Mn0.17Fe0.03O2 (NMF) cathode materials through wet subsequent heat treatment. Compared with the unmodified cathode materials, the modified cathode materials exhibit better electrochemical performance at high voltage. The specific discharge capacity of the modified cathode materials increased from 37.5 mAh g−1 (NMF) to 118.2 mAh g−1 after 200 cycles at 1 C and the retention rate increased from 21.18% to 69.77%. The samarium oxide coating effectively inhibits the reaction between the cathode materials and the electrolyte. Therefore, our study proposes a simple and scalable method for modifying nickel-rich cobalt-free cathode materials.

Microstructure and electrochemical properties of Mg/Nb/Zr co-doped LiNi0.94Mn0.04Al0.02O2 cathode materials

The increasing oil scarcity and environmental awareness have accelerated the rise of the new energy vehicle industry, but range and cost issues have hindered the rapid popularization of new energy vehicles. The Co-free Ni-rich layered cathode materials have received a wide attention due to their high energy density, low cost, and stable raw material supply. However, its structure and electrochemical stability still need to be further improved. In this study, the electrochemical properties of LiNi0·94Mn0·04Al0·02O2 (NMA), a Co-free Ni-rich layered cathode material, have been improved by co-doping of Mg, Nb, and Zr. Also, the effects of co-doping on the crystal structure, morphology and electrochemical properties of NMA cathode materials were investigated, too. The results show that the NMA material (NMA-333) with 0.9 mol% doping amount has the best electrochemical performance. The discharge-specific capacity in the first cycle at 1 C was 199.6 mAh g−1, and the capacity retention after 200 cycles reached 73.94 %, which is nearly 24 % higher than that of the original material (NMA-1.03). Meanwhile, the NMA-333 material has a relatively better rate performance, with a discharge-specific capacity of 125.2 mAh g−1 at 10 C. Moreover, the structure and morphology of the modified material were represented by SEM, TEM, XRD, and XPS. And the results showed that the co-doping modification could refine the primary particles of the NMA material, reduce the lithium-nickel mixing, and increase the lattice spacing. The XPS, SEM, and XRD of the post-cycle electrodes further showed that co-doping had stabilized the crystal structure, inhibited the generation and expansion of microcracks, and reduced the occurrence of harmful side reactions, thus improving the cycling performance of the NMA materials at high voltage. The method could be a feasible way to improve the electrochemical performance of layered high-nickel cobalt-free cathode materials.

Effective incorporation of cobalt near surface region for cobalt-free cathodes in lithium-ion batteries

Cobalt-free cathode materials, particularly Ni-rich layered oxide cathode materials, are ideal for electric vehicle Li-ion batteries, offering high energy density and cost-effectiveness. However, high Ni content in high-temperature synthesis leads to issues like increased Li/Ni cation mixing and reduced rate capability, mainly due to the absence of Co. Therefore, this study investigated the utilization of a small amount of Co instead of completely removing it to enhance electrochemical performance. A simple pre-calcination process was used to induce Co substitution beneath the Ni-rich layered oxide cathode materials surface. A coating process was also performed for comparison. The Li/Ni cation mixing in the Co-substituted sample during high-temperature calcination was 2.43%, demonstrating a superior value compared to the Co-coating process. Rate capability tests showed superior performance for Co-substituted sample (164.2 mAh g−1) at 2 C compared to coated sample (151.0 mAh g−1). Moreover, Co substitution improved not only the cycle stability but also the high-temperature stability at an elevated state of charge.This study focuses on the surface modification of cobalt-free cathode, providing direct insight into the effects of Co substitution and typical Co coating and suggests an optimal process that uses small amounts of Co.

Structure and Electrochemical Characterization of Nd0.5Ba0.5Zr0.8Fe0.2O3+δ Cobalt-Free Cathode Material for Intermediate-Temperature Solid Oxide Fuel Cells: An Experimental Investigation

Compared to other energy-generating technologies and energy conversion devices, intermediate-temperature solid oxide fuel cells (IT-SOFCs) have gained significant attention from energy experts due to its high energy density, moderate operating temperature (600 – 800 ℃), low emissions, and reliability. Enhancing the performance of IT-SOFCs requires suitable and excellent cathode materials. Thus, a perovskite-type Nd0.5Ba0.5Zr0.8Fe0.2O3+δ (NBZFO) material was synthesised via traditional solid-state reaction technique and analysed as a potential cathode material for IT-SOFCs. Analysis of x-ray diffraction data (XRD) revealed a single-phase perovskite material that crystallises in cubic space group (pm-3m). The thermal and electrochemical properties were analysed with the aid of thermogravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS). NBZFO has an electrical conductivity in air of 80 S/cm at 400 ℃, and a polarization resistance (PR) of 0.106 Ω∙cm2 at 800 ℃. TGA analysis reveals a slight loss in weight of about 0.58%, thereby suggesting a highly stable cathode material for IT-SOFC. Electrochemical investigation shows that NBZFO has good electronic and ionic conductivity and excellent oxygen stichometry. Further studies are required to understand the effects of varying B-site composition of the cathode material.

Pushing the Energy-Lifetime Frontier of Li-Ion Batteries with Optimized Ni-Rich, Co-Free NMA-W Cathodes

Especially in the electric vehicle industry where both high energy density and long lifetime batteries are sought, Ni-based cathode materials such as LiNi1−x−yMnxCoyO2 (NMC) and LiNi1−x−yCoxAlyO2 (NCA) provide a fitting compromise in capacity and cyclability. In recent years, the high cost of cobalt in addition to the problematic geopolitics surrounding cobalt mining have motivated research efforts toward cobalt-free cathode materials.1 However, Ni-rich materials are subject to inevitable failure mechanisms such as microcracking and parasitic reactions with the electrolyte which are further aggravated with an increase in Ni-content and in the absence of Co.2 Many strategies have been proposed to overcome these challenges such as doping and/or coating the cathode particles,3 but there remains a need to further increase energy density with minimal compromise to lifetime.In this work we present a cathode active material system designed to push Ni-rich and Co-free materials to the limit of their performance. This is done by choosing optimal polycrystalline particle size, a balance of Mn and Al content, and a sufficient amount of high-valence doping. Additionally, appropriate synthesis conditions are needed to obtain the desired morphology and infuse the intergranular boundaries with the W dopant. It is then important to choose an appropriate upper cutoff voltage during cycling to maximize energy while avoiding drastic crystal changes.4 This optimized NMA-W material system delivers specific capacity above 200 mAh/g while retaining 95% of its capacity without relying on any amount of Co.The series of NMA-W materials presented in this work were characterized and tested. Scanning electron microscopy (SEM) images were used to observe morphology and crystallite growth after synthesis. X-ray diffraction (XRD) analysis was conducted to monitor the crystal parameters and accelerated rate calorimetry (ARC) was used to assess the thermal stability and safety of the material. Compression tests were also conducted to study the strength of the particles and their propensity to crack under stress. Choi, J. U., Voronina, N., Sun, Y. K. & Myung, S. T. Recent Progress and Perspective of Advanced High-Energy Co-Less Ni-Rich Cathodes for Li-Ion Batteries: Yesterday, Today, and Tomorrow. Adv. Energy Mater. 10, 1–31 (2020).Li, H. et al. An Unavoidable Challenge for Ni-Rich Positive Electrode Materials for Lithium-Ion Batteries. (2019) doi:10.1021/acs.chemmater.9b02372.Yan, W., Yang, S., Huang, Y., Yang, Y. & Guohui Yuan. A review on doping/coating of nickel-rich cathode materials for lithium-ion batteries. J. Alloys Compd. 819, 153048 (2020).Nam, G. W. et al. Capacity Fading of Ni-Rich NCA Cathodes: Effect of Microcracking Extent. ACS Energy Lett. 4, 2995–3001 (2019).

Ageing and Post-Mortem Study of LNMO-Based Lithium Ion Battery Pouch Cells

Lithium ion batteries are nowadays widely employed in a variety of applications from consumer electronics to electric vehicles. Due to the rising demand for batteries, more affordable and sustainable batteries are needed that exhibit at the same time high energy densities, high power capabilities, long cycle life, and increased safety. One concept to meet these requirements is to develop cobalt-free cathode materials of which the high-voltage spinel LNMO (LiNi0.5Mn1.5O4) is a promising material due to its high energy density and high operating voltage of 4.7 V. However, the high operating voltage has also its drawbacks. Commonly used carbonate-based electrolytes oxidize at high voltages, leading to the continuous formation of a cathode-electrolyte interface (CEI). Additionally, LNMO is prone to transition metal dissolution which not only leads to a reduced stability of the cathode active material but due to migration and deposition of the transition metals on the anode surface also to an altered solid electrolyte interface (SEI) formation and significant impedance rise of the anode.1 Both ageing mechanisms provoke increased lithium loss and high resistances and thus a poor cycling performance.2, 3 In the Horizon 2020 LC-BAT5 project HYDRA, LNMO-based prototype pouch cells are developed and built. Herein, we want to present the results from the comprehensive analysis of their performance and cycling behavior. The influence of upper cut-off voltage, charge and discharge current rate as well as temperature on the degradation are thoroughly investigated by electrochemical methods such as differential voltage analysis and impedance spectroscopy. After cycling, selected cells are opened under argon atmosphere followed by electrochemical characterization as well as physical analysis such as SEM-EDX and XPS in order to get further insights into the underlying ageing mechanisms. We thereby reveal the main degradation mechanisms as a function of the cycling conditions and derive solutions on how to increase the cycle life.1. C. Zhan, T. Wu, J. Lu and K. Amine, Energy Environ. Sci.,11 (2), 243-257 (2018).2. J. Ma, P. Hu, G. Cui and L. Chen, Chem. Mater.,28 (11), 3578-3606 (2016).3. W. Li, Y.-G. Cho, W. Yao, Y. Li, A. Cronk, R. Shimizu, M. A. Schroeder, Y. Fu, F. Zou, V. Battaglia, A. Manthiram, M. Zhang and Y. S. Meng, J. Power Sources,473, (2020).Pseudo-OCV (a) and differential voltage analysis curves (b) of LNMO-graphite pouch cell cycled with 0.3C CCCV charge and 0.1C discharge at 25°C Figure 1

Effective reinforcement on the structural stability and electrochemical performances of ultra-high nickel cobalt free cathode material by co-doping

Ultra-high nickel ternary cathode material with high energy density is a very important material to meet the long driving range of new energy vehicles. However, cobalt has high toxicity, high price and supply chain risks, so the material is being developed in the direction of low cobalt or no cobalt. For ultra-high nickel cobalt free cathode material with high theoretical capacity (LiNi0.9Mn0.1O2, NM90), the lattice collapse and particle fragmentation caused by microcracks during long cycle will lead to inferior rate performance and cycle life. At present, the effect of different cobalt content on structure and electrochemical properties of cobalt-free cathode material is rarely reported. Therefore, based on cobalt-free precursors, the effects of proper Co doping on structure and electrochemical properties of NM90 material are studied in depth. It showed that proper Co doping can effectively reduce cationic mixing and improve Li+ diffusion rate of NM90 material. The NM90–1.5%Co material exhibits discharge specific capacity of 167.1 mA h g−1 after 100 cycles at 1C and 121.2 mA h g−1 after 200 cycles at 5C, respectively. Furthermore, NM90–1.5%Co material shows an initial discharge specific capacity of 144.1 mA h g−1 at 10C. Therefore, Co doping provides a feasible way to improve the structural stability and electrochemical performances of ultra-high nickel cobalt free cathode material.

Effect of Secondary Heat Treatment after a Washing on the Electrochemical Performance of Co-Free LiNi0.975 Al0.025 O2 Cathodes for Li-Ion Batteries.

The steadily growing electric vehicle market is a driving force in low-cost, high-energy-density lithium-ion battery development. To meet this demand,LiNi0.975 Al0.025 O2 (LNA), a high-energy-density and cobalt-free cathode material, has been developed using a low-cost and efficient co-precipitation and lithiation process. This article explores how further processing (i.e., washing residual lithium from the secondary particle surface and applying a secondary heat treatment at 650°C) changes the chemical environment of the surface and the electrochemical performance of the LNA cathode material. After washing, a nonconductive nickel oxide (NiO) phase is formed on the surface, decreasing the initial capacity in electrochemical tests, and suppressing high-voltage (H2) to (H3) phase transition results in enhanced cycle properties. Furthermore, the secondary heat treatment re-lithiates surface NiO back to LNAand increases the initial capacity with enhanced cycle properties. Electrochemical tests are performed with the cells without tap charge to suppress the H2 to H3 phase transition. Results reveal that avoiding charging cells at a high voltage for a long time dramatically improves LNA's cycle life. In addition, the gas analysis tests performed during charge and discharge to reveal how the amount of residual lithium compounds on the surface affects gas formation are studied.

High activity and stability of cobalt-free SmBa0.5Sr0.5Fe2O5+δ perovskite oxide as cathode material for solid oxide fuel cells

It is very important to develop cathode material with high stability and strong catalytic activity to realize the commercial application of solid oxide fuel cells (SOFCs). Here, we prepared a cobalt-free cathode material which partial substitution of Sr for Ba in SmBa0.5Sr0.5Fe2O5+δ (SBSF) sample and systematically investigated its electrochemical performance. Density functional theory (DFT) results showed that the oxygen vacancy formation energy of SBSF was lower than that of SmBaFe2O5+δ (SBF). The local density of state (LDOS) results showed that bandwidth center energy of SBSF between O-2p and Fe-3d obviously overlapped compared with parent SBF. The XRD spectra show that the SBSF formed a perovskite structure and had good chemical compatibility with La0.9Sr0.1Ga0.83Mg0.17O3-δ (LSGM) and CeO2-based electrolyte, respectively. At 800 °C, the polarization resistance and maximum power density of SBSF cathode on LSGM electrolyte were 0.023 Ω cm2 and 874 mWcm−2, respectively. In addition, the polarization resistance of SBSF electrode was stable during the 100 h test. The preliminary results show that SBSF oxide is a promising cathode material for SOFCs.

A review on new cobalt-free cathode materials for reversible solid oxide fuel cells

The exponential growth in the requirement of fuel cells and batteries leads to increased demand for cobalt due to its common use in high-performance Li-ion batteries and high-temperature fuel cells/electrolyzers. This sharp increment in demand raises concern about the availability of limited reserves of cobalt which can impact the price of cobalt. Moreover, the geographic limitations of cobalt resources may endanger the whole supply chain. In addition to all those, huge moral issues of cobalt mining are also another problem. Hence, leading battery, fuel cells and electrolyzer manufacturers are looking for sustainable alternatives to reduce cobalt dependency. A more specific limitation is shown in Solid Oxide Fuel Cells (SOFCs) cathode materials that contain cobalt. Incompatibilities have already been observed between the cathode materials containing cobalt and the electrolytes in terms of the thermal expansion coefficient mismatch during the transition of the operating temperature from high to low. An advantage of low operating temperatures is the reduction of material costs compared to high temperature. Increasing the electrochemical performance of the cell and eliminating thermal expansion coefficient difference problems are in concert aimed at the development of cobalt-free cathode materials. Therefore, cobalt-free cathode materials are vital for the sustainability of SOFCs and green transition of the energy sector since they can be used as cathode and anode material in symmetrical SOFCs which is also known as reversible SOFC (RSOFC). In this review, we comprehensively summarize the recent advances of cobalt-free perovskite cathode materials for intermediate temperature RSOFCs.

All dry in one step (ADIOS to water) synthesis of W-coated Li1+x(Ni0·7Mn0.3)1-xO2

Surface coatings have been used to improve the chemistry at the electrode-electrolyte interface of cathodes in lithium-ion batteries by forming a passivation film that can reduce side reactions with the electrolyte and can potentially offer enhanced electrochemical performance as well. Previous work in our group has shown that W-coated LiNiO2 electrode particles are more mechanically robust, which is reflected in the significantly improved cycling performance as microcracking is minimized. The application of these coatings, however, usually requires a separate processing step before or after lithiation of hydroxide precursors. Here, we propose combining a facile dry coating technique with the solid-state synthesis of cobalt-free cathode material Li1+x (Ni0·7Mn0.3)1-xO2 (Ni70Mn30), where W coated single crystal Ni70Mn30 is made in a one-step dry process from constituent compounds and a lithium source without any solvents. In this work, hydroxide precursors were bypassed completely and various precursor choices for the synthesis of cobalt-free materials were investigated. Cycling data shows that the W-coated single crystal Ni70Mn30 offers increased capacity without impacting lifetime and possesses excellent electrochemical performance. By adopting this direct synthesis approach, we believe that large amounts of wastewater and solid waste products can be eliminated while simplifying the cathode production process greatly.

Submicron single-crystal structure for enhanced structural stability of LiNi0.8Mn0.2O2 Ni-rich cobalt-free cathode materials

Submicron single-crystal structure for enhanced structural stability of LiNi0.8Mn0.2O2 Ni-rich cobalt-free cathode materials

Dynamic Structure Evolution of Extensively Delithiated High Voltage Spinel Li1+xNi0.5Mn1.5O4 x < 1.5.

High voltage spinel is one of the most promising next-generation cobalt-free cathode materials for lithium ion battery applications. Besides the typically utilized compositional range of LixNi0.5Mn1.5O4 0 < x < 1 in the voltage window of 4.90-3.00 V, additional 1.5 mol of Li per formula unit can be introduced into the structure, in an extended voltage range to 1.50 V. Theoretically, this leads to significant increase of the specific energy from 690 to 1190 Wh/kg. However, utilization of the extended potential window leads to rapid capacity fading and voltage polarization that lack a comprehensive explanation. In this work, we conducted potentiostatic entropymetry, operando XRD and neutron diffraction on the ordered stoichiometric spinel LixNi0.5Mn1.5O4 within 0 < x < 2.5 in order to understand the dynamic structure evolution and correlate it with the voltage profile. During the two-phase reaction from cubic (x < 1) to tetragonal (x > 1) phase at ∼2.8 V, we identified the evolution of a second tetragonal phase with x > 2. The structural evaluation during the delithiation indicates the formation of an intermediate phase with cubic symmetry at a lithium content of x = 1.5. Evaluation of neutron diffraction data, with maximum entropy method, of the highly lithiated phase LixNi0.5Mn1.5O4 with 2 < x < 2.5 strongly suggests that lithium ions are located on octahedral 8a and tetrahedral 4a positions of the distorted tetragonal phase I41amd. Consequently, we were able to provide a conclusive explanation for the additional voltage step at 2.10 V, the sloping voltage profile below 1.80 V, and the additional voltage step at ∼3.80 V.

Al, Zr dual-doped cobalt-free nickel-rich cathode materials for lithium-ion batteries

Nickel-rich and cobalt-free cathode materials have obvious advantages in the aspects of energy density and economic efficiency. However, these materials are restricted from being used in commercial lithium-ion batteries due to the problems of poor structural stability and rate capability. In this study, the aluminum and zirconium dual-doped Co-free Ni-rich LiNi0.96Mn0.04O2 cathode material (NMAZ) is prepared by a facile high-temperature solid-phase method. The obtained NMAZ shows low cation disordering degree owing to the stability of transition metal slabs induced by strong Al–O and Zr–O bonds. Besides, the kinetics of lithium-ion diffusion is significantly improved by larger c-axis and the fast lithium-ion conducting Li2ZrO3 layer on the interface. As a result, NMAZ shows an improved capacity retention of 70.3% at 1C after 100 cycles under an elevated temperature (45 ​°C), compared with 50.5% of pure LiNi0.96Mn0.04O2. In addition, it exhibits splendid rate performance even at higher C-rate and better thermal stability compared to bare LiNi0.96Mn0.04O2. Hence, the Al, Zr dual-doped modification is beneficial to improving the structural stability and electrochemical performance of the Ni-rich and Co-free layered oxide cathodes for Li-ion batteries.

LiNi0.8Fe0.1Al0.1O2 as a Cobalt-Free Cathode Material with High Capacity and High Capability for Lithium-Ion Batteries

Obtaining cathode materials with high capacity and cycle stability is one of the main challenges regarding the success of electric vehicle technologies. However, most of the widely used materials with these properties involve the use of toxic and expensive cobalt as the active material. To overcome this challenge, this work proposes a novel cobalt-free cathode material, synthesized for the first time using a solid-state reaction, whose general formula is LiNi0.8Fe0.1Al0.1O2 (NFA). This class of materials offers high capacity and reduces the battery costs by removing cobalt, without jeopardizing the structural stability and safety of the NFAs. The morphology and the structural properties of the obtained NFA cathode material were characterized using different techniques, e.g., scanning electronic microscopy, X-ray diffraction, X-ray fluorescence, and infrared and Raman spectroscopies. The electrochemical activity and diffusivity of the Li-ion during lithium removal and its insertion into the bulk of the NFA cathode demonstrated high-yield specific capacities of ≈180 mAh g−1 at 0.1C, along with a reasonable rate capability and cycling stability, with a capacity retention of ≈99.6% after 100 charge/discharge cycles at a rate of C/2, and whose operando X-ray diffraction experiments have been used to study the crystallographic transitions during the lithiation–delithiation reaction.

Tuning Cu-Content La1-xSrxNi1-yCuyO3-δ with Strontium Doping as Cobalt-Free Cathode Materials for High-Performance Anode-Supported IT-SOFCs.

Cu-content La1-xSrxNi1-yCuyO3-δ perovskites with A-site strontium doping have been tuned as cobalt-free cathode materials for high-performance anode-supported SOFCs, working at an intermediate-temperature range. All obtained oxides belong to the R-3c trigonal system, and phase transitions from the R-3c space group to a Pm-3m simple perovskite have been observed by HT-XRD studies. The substitution of lanthanum with strontium lowers the phase transition temperature, while increasing the thermal expansion coefficient (TEC) and oxygen non-stoichiometry δ of the studied materials. The thermal expansion is anisotropic, and TEC values are similar to commonly used solid electrolytes (e.g., 14.1 × 10-6 K-1 for La0.95Sr0.05Ni0.5Cu0.5O3-δ). The oxygen content of investigated compounds has been determined as a function of temperature. All studied materials are chemically compatible with GDC-10 but react with LSGM and 8YSZ electrolytes. The anode-supported SOFC with a La0.95Sr0.05Ni0.5Cu0.5O3-δ cathode presents an excellent power density of 445 mW·cm-2 at 650 °C in humidified H2. The results indicate that La1-xSrxNi1-yCuyO3-δ perovskites with strontium doping at the A-site can be qualified as promising cathode candidates for anode-supported SOFCs, yielding promising electrochemical performance in the intermediate-temperature range.

Low Cost, Solvent-Free Lithium-Ion Battery Electrode Manufacturing Based on Electrostatic Dry Powder Coating

Conventional industrial processes for the manufacture of Lithium-Ion Battery (LIB) electrodes are costly and not environmentally friendly. The state-of-the-art slurry casting technique utilizes a large amount of toxic N-methly pyrollidinone (NMP), necessitating significant energy and capital costs associated with electrode drying and solvent recovery.Electrostatic Dry Powder Deposition (EDPD) is well established in many industries as an effective method of achieving well-adhered and uniform coatings of controlled thickness & composition. Recently, a small number of studies have demonstrated the viability of EDPD in LIB electrode manufacture, achieving cell capacities similar to, or exceeding, those from slurry casting. Crucially, this approach eliminates the need for solvent usage. Nevertheless, several challenges remain before EDPD can be adopted within the LIB industry. In particular, achieving adequate dispersion of powder materials and a level of adhesion sufficient for use in standard roll-2-roll lines.With the goal of developing & demonstrating the viability of the EDPD process, this work will present a solvent-free approach, coupled with innovative methods to improve adhesion and overall coating quality. The high voltage spinel cathode Lithium Nickel Manganese Oxide (LNMO) was utilized as a demonstrator material, as it can provide high energy density cells without the use of expensive and rare cobalt. Results will include: (a) development of EDPD equipment and appropriate process parameters, (b) optimization of coating formulation, (c) adhesion enhancement through through the use of in-situ heating and post-deposition treatments, (d) electrochemical analysis of EDPD electrodes and benefits compared with slurry casting, (e) full process cost analysis. The presentation will conclude with a discussion of the potential of this new manufacturing technique to disrupt the LIB industry.Rechargeable lithium-ion batteries (LIBs) are ubiquitous in mostly every electronic device. However, the process of manufacturing LIBs is costly and not environmentally friendly. State of the art LIB electrode manufacturing is carried out using slurry casting. A mixture of active material (most commonly containing Cobalt), a binder and a conductive additive are mixed with a solvent and cast onto a substrate. This process is energy-intensive and requires significant capital for drying equipment and processes and the recovery of toxic solvents, such as N-methyl pyrrolidone (NMP).Utilising an EDPD process with a Cobalt free active material such as LNMO in place of the slurry casting process would eliminate the need to use toxic solvents, thereby significantly reducing the manufacturing time and cost. Additionally, LNMO can work as a replacement for the next-generation lithium-ion battery Cobalt-free cathode materials due to its high lithiation/delithiation potential, > 4.5 V compared with 3 – 4 V in the case of more conventional cathode material.The EDPD process presented has demonstrated that a reduction in cost of over 35% can be achieved when tested with LNMO, polyvinylidene fluoride (PVDF) as binder and Carbon Black (CB) as a conductive additive, by eliminating the use of NMP and Cobalt from the process. This is based on a comparison carried out with 1kg of active material mix. There are challenges associated with dry powder electro manufacture for LIBs, such as achieving good adhesion, tortuosity, and obtaining an even dispersion and thickness of the coating. This work addresses these challenges and develops an innovative dry powder deposition method assisted with a low power laser to improve adhesion in a scalable manner.Using a combination of EDPD, low heat and low power laser as an enhancement for the adhesion process in electrode manufacture create an innovative opportunity to remove the toxic solvents to achieve good dry powder depositions making the process less energy demanding and more environmentally friendly. The present research will focus on how to produce dry electrodes with electrostatic coating manufacture, the process innovation of adding a Laser to improve the adhesion and electrochemical testing to quantify the LIB's performance when using this approach.Early research has shown that the manufactured electrodes have similar capacity retention and improved rate capability in lithium-ion batteries when compared to the current state of the art of slurry casting. The simple process operation offers flexibility in scalable production and modularity for future development and commercial implementation.

Hydrothermal synthesis of Co-free NMA cathodes for high performance Li-ion batteries

Scalable and sustainable production of high voltage cathodes is required to meet the increasing demands for Li-ion batteries. Additionally, the anticipated scarcity of critical materials like cobalt necessitates demonstration of Co-free alternatives that can match the performance metrics of conventional cathodes. Herein, a hydrothermal synthesis route for production of a new class of high-capacity, cobalt-free cathode material, LiNi0.9Mn0.05Al0.05O2 (NMA9055) for next-generation Li-ion batteries is reported. The synthesized cathode material shows high crystallinity and purity with monodispersed spherical morphology. Extensive electrochemical, structural, and post-mortem characterization of this novel NMA material is carried out. NMA-Li half cells show an initial discharge capacity of 200 mAh/g with a 96% capacity retention over 100 cycles when cycled between 3.0 and 4.4 V. On the other hand, NMA full cells with Li4Ti5O12 (LTO) electrodes as the anode, show an initial discharge capacity of 186 mAh/g with 81% capacity retention over 200 cycles. Post-mortem structural and morphological characterization show that the NMA morphology and crystal structure do not degrade significantly over 200 charge/discharge cycles. This new class of cobalt free cathode material containing nickel, manganese and aluminum synthesized by an ammonia-free synthesis route is expected to provide a facile solution towards sustainable cathode production.

Ba0.95La0.05Fe0.8Ni0.2O3−δ perovskite as efficient cathode electrocatalysts for proton-conducting solid oxide fuel cells

The key issue that limits the electrochemical performance of proton-conducting solid oxide fuel cells (H+-SOFCs) is the sluggish kinetics of the oxygen reduction reaction (ORR) of cathode at intermediate and low temperatures. Herein, oxygen vacancy engineering is conducted on cobalt-free Ba0.95La0.05FeO3−δ (BLF) by nickel substitution, which is confirmed by density functional theory computations. Nickel-substituted BLF material (Ba0.95La0.05Fe1−xNixO3−δ (x = 0, 0.1, 0.2, 0.3)) can promote the generation of oxygen vacancies and improve catalytic activity, which is found to be in line with the experimental results of XPS. The phase structure, microstructure, and electrochemical performance of Ba0.95La0.05Fe0.8Ni0.2O3−δ (BLFNi0.2) are well-investigated. The single cells with the BLFNi0.2-BaCe0.7Zr0.1Y0.1Yb0.1O3−δ (BCZYYb) composite cathode achieve low polarization resistance (Rp) of 0.099 Ω cm2 and a peak power density of 631 mW cm−2 at 700 °C while maintaining good durability for 120 h with no observable degradation. The results demonstrate that Ni-doped BLF is a promising cobalt-free cathode material for H+-SOFCs.

LiNi&lt;sub&gt;0.7&lt;/sub&gt;Mn&lt;sub&gt;0.3&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; as a Cheap Cobalt Free Nickel Rich Cathode Material for High-Performance Li-Ion Batteries

A high-quality Lithium Nickel Manganese Oxide (LiNi0.7Mn0.3O2) material is successfully synthesized via co-precipitation. The precursors for lithium rechargeable batteries have been prepared using starting materials (NiCl2.6H2O and MnSO4.H2O) with precipitating agents of oxalic acid and sodium hydroxide, Ethylene diamine tetra acetic (EDTA) and sodium hydroxide, and sodium carbonate for oxalate co-precipitation, hydroxide co-precipitation, and carbonate co-precipitation, respectively. Then, the precursors were calcined at 500°C for 5 hours, mixed with Li2CO3, and sintered at 850°C for 15 hours under oxygen. X-ray Diffraction (XRD) analysis results show that the particles obtained by oxalate co-precipitation (LiNi0.7Mn0.3O2-C2O4) have higher crystallinity and more uniform particle shape than hydroxide co-precipitation and carbonate co-precipitation. The Fourier Transform Infrared (FTIR) spectroscopy characterization shows no carbonate group peak in the LiNi0.7Mn0.3O2-C2O4. Furthermore, electrochemical tests were analyzed by evaluating the charge/discharge curves and cycling performance. The highest specific discharge capacity of 122 mAh/g was achieved by the LiNi0.7Mn0.3O2-C2O4 sample, which also had a low capacity loss (22.7%), retaining 89.9% of its initial specific capacity at 0.5C between 2.5 and 4.25 V after 45 cycles. Based on these results, a cheap cobalt-free cathode material is promising for a new commercialized Li-ion battery.