Search Results (90)

In this study, a selection of active materials were coated onto commercially available intermediate modulus carbon fibers to form and analyze the performance of novel composite cathodes for structural power composites. Various slurries containing polyvinylidene fluoride (PVDF), active material powders, 1-methyl-2-pyrrolidone (NMP) and carbon black (CB) were used to coat carbon fiber tows by immersion. Four active materials—lithium cobalt oxide (LCO), lithium iron phosphate (LFP), lithium nickel manganese cobalt oxide (NMC), and lithium nickel cobalt aluminum oxide (NCA)—were individually tested to assess their electrochemical reversibility. The cells were prepared with a polymer separator and liquid electrolytes and assembled in 2025-coin cells. Electrochemical analysis of the cathode materials showed that at C/5 and room temperature the measured capacities ranged from 39.8 Ah kg⁻¹ to 64.7 Ah kg⁻¹ for the LFP and NCA active materials, respectively. The full cells exhibited capacities of 18.1, 23.5, 27.2, and 28.2 Ah kg⁻¹ after 55 cycles for LFP, LCO, NCA, and NMC811, respectively. Finally, visual and elemental analysis were performed via scanning electron microscope (SEM) and energy-dispersive x-ray (EDX) confirming desirable surface coverage and successful transfer of the active materials onto the carbon fiber tows. Full article

The salt flotation of graphite in the presence of lithium nickel manganese cobalt oxide (NMC) was assessed by performing colloidal probe atomic force microscopy (CP-AFM) on sessile gas bubbles and conducting batch flotation tests with model lithium-ion-battery black mass. The modeling of film drainage and detachment during particle–bubble interactions provides insight into the fundamental microprocesses during salt flotation, a special variant of froth flotation. The interfacial properties of particles and gas bubbles were tailored with salt solutions containing sodium chloride and sodium acetate buffer. Graphite particles can attach to gas bubbles under all tested conditions in the range pH 3 to pH 10. The attractive forces for spherical graphite are strongest at high salt concentrations and pH 3. The conditions for the attachment of NMC to gas bubbles were evaluated with simulations using the Stokes–Reynolds–Young–Laplace model for film drainage, under consideration of DLVO forces and a hydrodynamic slip to account for irregularities of the particle surface. CP-AFM measurements in the capillary force regime provide additional parameters for the modeling of salt flotation, such as the force and work of detachment. The contact angles of graphite and NMC particles during retraction and detachment from gas bubbles were obtained from a quasi-equilibrium model using CP-AFM data as input. All CP-AFM experiments and theoretical results suggest that pristine NMC particles do not attach to gas bubbles during flotation, which is confirmed by the low rate of NMC recovery in batch flotation tests. Full article

There is an increasing demand for the development of efficient and sustainable battery recycling processes. Currently, many recycling processes rely on toxic inorganic acids to recover materials from high-value battery chemistries such as lithium nickel manganese cobalt oxides (NMCs) and lithium cobalt oxide (LCOs). However, as cell manufacturers seek more cost-effective battery chemistries, the value of the spent battery value chain is increasingly diluted by chemistries such as lithium iron phosphate (LFPs). These cheaper alternatives present a difficulty when recycling, as current recycling processes are geared towards dealing with high-value chemistries; thus, the current processes become less economical. To date, much research is focused on treating a single battery chemistry; however, often, the feed material entering a battery recycling facility is contaminated with other battery chemistries, e.g., LFP feed contaminated with NMC, LCO, or LMOs. This research aims to selectively leach various battery chemistries out of a mixed feed material with the aid of a green organic acid, namely oxalic acid. When operating at the optimal conditions (2% solids, 0.25 M oxalic acid, natural pH around 1.15, 25 °C, 60 min), this research has proven that oxalic acid can be used to selectively dissolve 95.58% and 93.57% of Li and P, respectively, from a mixed LFP-NMC mixed feed, all while only extracting 12.83% of Fe and 8.43% of Mn, with no Co and Ni being detected in solution. Along with the high degree of selectivity, this research has also demonstrated, through varying the pH, that the selectivity of the leaching system can be altered. It was determined that at pH 0.5 the system dissolved both the NMC and LFP chemistries; at a pH of 1.15, the LFP chemistry (Li and P) was selectively targeted. Finally, at a pH of 4, the NMC chemistry (Ni, Co and Mn) was selectively dissolved. Full article

This paper explores the implementation of battery electric vehicles (BEVs) in underground mining operations, focusing on their benefits, challenges, and safety considerations. The study examines the shift from traditional diesel-powered machinery to BEVs in response to increasing environmental concerns and stricter emission regulations. It discusses various lithium-ion battery chemistries used in BEVs, particularly lithium–iron–phosphate (LFP) and nickel–manganese–cobalt (NMC), comparing their performance, safety, and suitability for underground mining applications. The research highlights the significant benefits of BEVs, including reduced greenhouse gas emissions, improved air quality in confined spaces, and potential ventilation cost savings. However, it also addresses critical safety concerns, such as fire risks associated with lithium-ion batteries and the emission of toxic gases during thermal runaway events. The manuscript emphasises the importance of comprehensive risk assessment and mitigation strategies when introducing BEVs to underground mining environments. It concludes that while BEVs offer promising solutions for more sustainable and environmentally friendly mining operations, further research is needed to ensure their safe integration into underground mining practices. This study contributes valuable insights to the ongoing discussion on the future of mining technology and its environmental impact. Full article

Batteries are a key element in the development of both battery-operated and hybrid trains. For this type of system, the most common anode choice is LTO (lithium titanate), as the adoption of lithium titanate instead of graphite for anodes ensures an unrivaled level of reliability, especially against calendar aging. LTO also ensures prolonged load-cycle lifespans. However, LTO’s known drawbacks involve its high production cost and mediocre energy density, which is mainly due to its high anodic potential compared to graphite. In this study, we perform a rapid identification of an LiNMC (lithium, nickel, manganese, and cobalt) cell and propose some preliminary scaled HIL (hardware in the loop) and SIL (software in the loop) testing, aiming to verify the possible usage of LiNMC cells for railway applications. Full article

Lithium-ion batteries (LIBs) are widely used in diverse applications, ranging from portable ones to stationary ones. The appropriate handling of the immense amount of spent batteries has, therefore, become significant. Whether recycled or repurposed for second-life applications, knowing their chemistry type can lead to higher efficiency. In this paper, we propose a novel machine learning-based approach for accurate chemistry identification of the electrode materials in LIBs based on their temperature dynamics under constant current cycling using gated recurrent unit (GRU) networks. Three different chemistry types, namely lithium nickel cobalt aluminium oxide cathode with silicon-doped graphite anode (NCA-GS), nickel cobalt aluminium oxide cathode with graphite anode (NCA-G), and lithium nickel manganese cobalt oxide cathode with graphite anode (NMC-G), were examined under four conditions, 0.2 C charge, 0.2 C discharge, 1 C charge, and 1 C discharge. Experimental results showed that the unique characteristics in the surface temperature measurement during the full charge or discharge of the different chemistry types can accurately carry out the classification task in both experimental setups, where the model is trained on data under different cycling conditions separately and jointly. Furthermore, experimental results show that the proposed approach for chemistry type identification based on temperature dynamics appears to be more universal than voltage characteristics. As the proposed approach has proven to be efficient in the chemistry identification of the electrode materials LIBs in most cases, we believe it can greatly benefit the recycling and second-life application of spent LIBs in real-life applications. Full article

Lithium-ion batteries risk failing when subjected to different abuse tests, resulting in gas and flames. In this study, 5 Ah nickel manganese cobalt oxide (NMC) pouch cells were subjected to external heating; overcharge at rates of 2.5, 5 and 10 A; and nail penetration. Tests were conducted in air and N₂ atmospheres. Additional external heat tests were performed on cells at 5, 25, 50, and 75% SoC and on two, three, and four cell blocks. Gas volumes were calculated, and the gas composition was given for H₂, CO, CO₂, C₂H₄, C₂H₆, CH₄, C₃H₆, and C₃H₈. For tests under an air atmosphere at 100% SoC, the volume of gas varied between abuse methods: 3.9 L (external heat), 6.4 L (overcharge), and 8.9 L (nail penetration). The gas composition was found to predominantly contain H₂, CO₂, and CO for all abuse methods; however, higher concentrations of H₂ and CO were present in tests performed under N₂. External heat tests at different SoCs showed that the gas volume decreased with SoC. Overall, the type of abuse method can have a large effect on the gas volume and composition produced by cell failure. Full article

This paper presents entropy measurements for a large set of commercial Li-ion cells. We present entropy data on full cells with a variety of common Li-ion cell electrode chemistries; graphite, hard carbon, lithium-titanium-oxide (LTO), lithium cobalt-oxide (LCO), nickel manganese cobalt oxides (NMC), nickel cobalt aluminium oxide (NCA), lithium iron-phosphate (LFP), as well as electrodes with mixes of these. All data were collected using an accelerated potentiometric method in steps of approximately 5% State-of-Charge (SoC) across the full SoC window. We observe that the entropy profiles depend on the chemistry of the Li-ion cells, but that they also vary between different commercial cells with the same chemistry. Entropy contributions are quantified with respect to both, their means, positive and negative contributions as well as their SoC variation. In addition, we present how different cyclic ageing temperatures change the entropy profiles for a selected commercial Li-ion cell through ageing. A clear difference in entropy profiles is observed after a capacity loss of 20%. This difference can be attributed to different ageing mechanisms within the Li-ion cells, leading to changes in the balancing of electrodes, as well as changes in the electrode materials. Full article

Achieving accurate battery state of health (SOH) estimation is crucial, but existing methods still face many challenges in terms of data quality, computational efficiency, and cross-scenario generalization capabilities. This study proposes a hybrid deep learning framework incorporating transfer learning to address these challenges. The framework integrates inception depthwise convolution (IDC), channel reduction attention (CRA) mechanism, and staged training strategy to improve the accuracy and generalization ability of SOH estimation. The IDC module of the proposed model is capable of extracting battery degradation time series features from multiple scales while reducing the computational overhead. The CRA module effectively reduces the computational complexity and memory usage of global feature capture by compressing the channel dimensions. A well-designed pre-training/fine-tuning two-stage training strategy achieves accurate cross-scene SOH estimation by utilizing large-scale source-domain data to learn generalized aging features and then uses a small amount of new data to quickly fine-tune the base model. The proposed method is validated using two publicly available datasets, including 54 nickel cobalt manganese oxide (NCM) cells and 16 nickel manganese cobalt oxide (NMC) cells. The experimental results show that the root mean square error (RMSE) of the model on the NCM and NMC datasets is 0.522% and 0.283%, respectively, with a coefficient of determination (R²) not less than 0.98 and mean absolute percentage error (MAPE) of 0.431% and 0.22%, respectively. The proposed method not only achieves high-precision SOH estimation among the same type of batteries but also demonstrates strong generalization ability under different battery chemistries and scenarios. Full article

Lithium nickel manganese cobalt oxides (NMCs) are widely used as cathode materials in commercial batteries. Efforts have been made to enhance battery energy density and stability by adjusting the element ratio. Nickel-rich NMC shows promise due to its high capacity; however, its commercial viability is hindered by severe capacity fade, primarily caused by poor mechanical stability. To address this, understanding the chemo-mechanical behavior of Ni-rich NMC is crucial. The mechanical failure of Ni-rich NMC materials during battery operation has been widely studied through theoretical approaches to identify possible solutions. The elastic properties are key parameters for structural analysis. However, experimental data on NMC materials are scarce due to the inherent difficulty of measuring the properties of electrode active particles at such a small scale. In this study, we employ molecular dynamics (MDs) simulations to investigate the elastic properties of NMC materials with varying compositions (NMC111, NMC532, NMC622, NMC721, and NMC811). Our results reveal that elasticity increases with nickel content, ranging from 200 GPa for NMC111 to 290 GPa for NMC811. We further analyze the contributing factors to this trend by examining the individual components of the elastic properties. The simulation results provide valuable input parameters for theoretical models and continuum simulations, offering insights into strategies for reducing the mechanical instability of Ni-rich NMC materials. Full article

One of the major concerns for battery electric vehicles (BEVs) is the occurrence of thermal runaway (TR), usually of a single cell, and its propagation to adjacent cells in a battery pack. To guarantee sufficient safety for the vehicle occupants, the TR mechanisms must be known and predictable. In this work, we compare thermal runaway scenarios using different initiation protocols (heat–wait–seek, constant heating, nail penetration) and battery chemistries (nickel manganese cobalt oxide, NMC; lithium iron phosphate, LFP; and sodium-ion batteries, SIB) with the cells in a fully charged state. Our goal is to specifically trigger a variety of different possible TR scenarios (internal failure, external hotspot, mechanical damage) with different types of chemistries to obtain reliable data that are subsequently employed for modeling and prediction of the phenomenon. The safety of the tested cells depending on their chemistry can be summarized as LFP > SIB >> NMC. The data of the TR experiments were used as the basis for high-fidelity modeling and predicting of TR phenomena in 3D. The models simulated reaction rates, represented by the typically employed Arrhenius approach. The effects of the investigated TR triggering methods and cell chemistries were represented with sufficient accuracy, enabling the application of the models for the simulation of thermal propagation in battery packs. Full article

Thermal runaway (TR) has become a critical safety concern with the widespread use of lithium-ion batteries (LIBs) as an energy storage solution to meet the growing global energy demand. This issue has become a significant barrier to the expansion of LIB technologies. Addressing the urgent need for safer LIBs, this study developed a comprehensive model to simulate TR in cylindrical 18650 nickel cobalt manganese (NMC) LIBs. By incorporating experiments with LG^®-INR18650-MJ1 cells, the model specifically aimed to accurately predict critical TR parameters, including temperature evolution, internal pressure changes, venting phases, and mass loss dynamics. The simulation closely correlated with experimental outcomes, particularly in replicating double venting mechanisms, gas generation, and the characteristics of mass loss observed during TR events. This study confirmed the feasibility of assuming proportional relationships between gas generation and the cell capacity and between the mass loss from solid particle ejection and the total mass loss, thereby simplifying the modeling of both gas generation and mass loss behaviors in LIBs under TR. Conclusively, the findings advanced the understanding of TR mechanisms in LIBs, providing a solid foundation for future research aimed at mitigating risks and promoting the safe integration of LIBs into sustainable energy solutions. Full article

This study presents a comprehensive analysis of the synthesis techniques and the effects of aluminum doping on nickel-manganese-cobalt (NMC) 811 cathode materials. Our research focuses on the comparison of two different synthesis methods. Hydroxide co-precipitation is followed by solid-state calcination for polycrystalline (PC) cathodes and molten salt calcination for single-crystalline (SC) cathodes. In addition, the study systematically integrates aluminum dopants at different stages of these processes. This study aims to examine how various doping methods affect the structural characteristics, morphological features, and electrochemical performance of NMC cathodes.This investigation employs a thorough characterization approach, utilizing techniques such as X-ray diffraction (XRD), various microscopy methods, and galvanostatic cycling tests, our results illustrate the complexity of the synthesis parameters that influence the capacity retention and performance of the samples produced. Full article

It is necessary to maintain safe, efficient, and compatible energy storage systems to meet the high demand for electric vehicles (EVs). Lithium manganese nickel cobalt (NMC) and lithium ferro phosphate (LFP) batteries are the most commonly used lithium batteries in EVs. It is imperative to note that batteries are classified according to their electrochemical performance. A number of factors play a crucial role in determining how efficiently batteries can be used. These factors include the cell temperature, energy density, self-discharge, current limits, aging, and performance measurements. This paper offers a proposed electrothermal model for comparison between LFP and NMC batteries. This model demonstrates the different behaviors according to their application in EVs. This is carried out through studies of state of charge (SoC), state of health (SoH), thermal runaway, self-discharge, and remaining useful life (RUL) in EVs. According to numerical analysis, this paper examines how these different types of batteries behave in EVs to assist in the selection of the most suitable battery taking into account the operating temperature and discharge current using a helpful thermoelectric model reflecting battery safety and life span effectively. Using MATLAB Simulink, the data selected in the electrothermal model are combined from a number of references that are incorporated into lookup tables that affect the change in values in the electrothermal model. The cells are implemented in an EV system using a current test to examine the measured current that goes in and comes out of the battery cells during charging and discharging processes taking into account motoring and regenerative braking for a specified drive cycle time and a number of discharging cycles. It was found that LFP batteries have better stability for open circuit voltages of 3.34 volts over a wide range of conducted temperatures. NMC batteries, on the other hand, exhibit some open circuit voltage variation of 0.053 volts over the temperature range used. Furthermore, the self-discharging current of LFP batteries was about 12 times lower than that of NMC batteries. Compared to LFP batteries, NMC batteries have a higher energy density per unit of mass of 150%, which reflects their greater discharge range. As a result of temperature effects, it has been revealed that LFP batteries are about two times more stable during discharging than NMC batteries, particularly at higher temperatures, such as 45 degrees. Full article

This study explores the optimization of hydrometallurgical processes for recycling lithium-ion batteries (LIBs) containing a mixture of lithium iron phosphate (LFP) and nickel–manganese–cobalt (NMC) cathodes. Two approaches were investigated: acid-excess leaching and acid-deficient leaching with residue recirculation. A design of experiments (DoE) framework was applied to assess the impact of key parameters, including sulfuric acid and hydrogen peroxide concentrations, as well as solid-to-liquid (S/L) ratios, on the dissolution yields of target metals (Ni, Mn, Co, and Li). Acid-excess leaching achieved nearly complete dissolution of target metals but required additional purification steps to remove impurities. Acid-deficient leaching with a 60% recirculation of leaching residue improved dissolution yields by up to 12.5%, reduced reagent consumption, and minimized operational complexity. The study also evaluated separation strategies for manganese and cobalt through solvent extraction. Results indicate that while acid-excess leaching offers higher yields, acid-deficient leaching with residue recirculation is more cost-effective and environmentally friendly. These findings provide valuable insights for developing sustainable LIB recycling technologies. Full article