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The global transition to electric vehicles and renewable energy systems continues to gain support from governments and investors. As a result, the demand for electric energy storage systems such as lithium-ion batteries (LIBs) has substantially increased. This is a significant motivator for reassessing end-of-life strategies for these batteries. Most importantly, a strong focus on transitioning from landfilling to an efficient recycling system is necessary to ensure the reduction of total global emissions, especially those from LIBs. Furthermore, LIBs contain many resources which can be reused after recycling; however, the compositional and component complexity of LIBs poses many challenges. This study focuses on the recycling and reusing of copper (Cu) and aluminum (Al) foils, which are the anode and cathode current-collectors (CCs) of LIBs. For this purpose, methods for the purification of recycled Cu and Al CCs for reusing in LIBs are explored in this paper. To show the effectiveness of the purification, the recycled CCs are used to make new LIBs, followed by an investigation of the performance of the made LIBs. Overall, it seems that the LIBs' CCs can be reused to make new LIBs. However, an improvement in the purification method is still recommended for future work to increase the new LIB cycling. [ABSTRACT FROM AUTHOR]

Manual disassembly of the lithium-ion battery (LIB) modules of electric vehicles (EVs) for recycling is time-consuming, expensive, and dangerous for technicians or workers. Dangers associated with high voltage and thermal runaway make a robotic system suitable for the automated or semi-automated disassembly of EV batteries. In this paper, we explore battery disassembly using industrial robots. To understand the disassembly process, human workers were monitored, and the operations were analyzed and broken down into gripping and cutting operations. These operations were selected for automation, and path planning was performed offline. For the gripper, a linear quadratic regulator (LQR) control system was implemented. A system identification method was also implemented in the form of a batch least squares estimator to form the state space representation of the planar linkages used in the control strategy of the gripper. A high-speed rotary cut-off wheel was adapted for the robot to perform precise cutting at various points in the battery module case. The simulation results were used to program an industrial robot for experimental validation. The precision of the rotary cutter allowed for a more direct disassembly method as opposed to the standard manual method. It was shown that the robot was almost twice as fast in cutting but slower in pick and place operations. It has been shown that the best option for disassembly of a LIB pack is a human–robot collaboration, where the robot could make efficient cuts on the battery pack and the technician could quickly sort the battery components and remove connectors or fasteners with which the robot would struggle. This collaboration also reduces the danger encountered by the technician because the risk of shorting battery cells while cutting would be eliminated, but the time efficiency would be significantly improved. This paper demonstrates that a robot offers both safety and time improvements to the current manual disassembly process for EV LIBs. [ABSTRACT FROM AUTHOR]

The battery pack in electric vehicles is subjected to road-induced vibration and this vibration is one of the potential causes of battery pack failure, especially once the road-induced frequency is close to the natural frequency of the battery when resonance occurs in the cells. If resonance occurs, it may cause notable structural damage and deformation of cells in the battery pack. In this study, the natural frequencies and mode shapes of a commercial pouch lithium-ion battery (LIB) are investigated experimentally using a laser scanning vibrometer, and the effects of the battery supporting methods in the battery pack are presented. For this purpose, a test setup to hold the LIB on the shaker is designed. A numerical analysis using COMSOL Multiphysics software is performed to confirm that the natural frequency of the designed test setup is much higher than that of the battery cell. The experimental results show that the first natural frequency in the two-side supported and three-side supported battery is about 310 Hz and 470 Hz, respectively. Although these frequencies are more than the road-induced vibration frequencies, it is recommended that the pouch LIBs are supported from three sides in battery packs. The voltage of the LIB is also monitored during all experiments. It is observed that the battery voltage is not affected by applying mechanical vibration to the battery. [ABSTRACT FROM AUTHOR]

Summary: The charge, discharge, and total energy efficiencies of lithium‐ion batteries (LIBs) are formulated based on the irreversible heat generated in LIBs, and the basics of the energy efficiency map of these batteries are established. This map consists of several constant energy efficiency curves in a graph, where the x‐axis is the battery capacity and the y‐axis is the battery charge/discharge rate (C‐rate). In order to introduce the energy efficiency map, the efficiency maps of typical LIB families with graphite/LiCoO2, graphite/LiFePO4, and graphite/LiMn2O4 anode/cathode are generated and illustrated in this paper. The methods of usage and applications of the developed efficiency map are also described. To show the application of the efficiency map, the effects of fast charging, nominal capacity, and chemistry of typical LIB families on their energy efficiency are studied using the generated maps. It is shown how energy saving can be achieved via energy efficiency maps. Overall, the energy efficiency map is introduced as a useful tool for engineers and researchers to choose LIBs with higher energy efficiency for any targeted applications. The developed map can be also used by energy systems designers to obtain accurate efficiency of LIBs when they incorporate these batteries into their energy systems. Energy efficiency map for Li‐ion batteries (LIBs) is introduced.Determination of energy efficiency is important for LIBs operating at ≥C/2.This map can be used for selection of LIBs with higher efficiency.This map can be used to find the LIB efficiency when it is incorporated into an energy system.This map can be used to study effects of fast charging, capacity, C‐rate, and chemistry of LIBs. [ABSTRACT FROM AUTHOR]

A multiscale platform has been developed to model lithium ion battery (LIB) electrodes based on the real microstructure morphology. This multiscale framework consists of a microscale level where the electrode microstructure architecture is modeled and a macroscale level where discharge/charge is simulated. The coupling between two scales are performed in real time unlike using common surrogate based models for microscale. For microscale geometry 3D microstructure is reconstructed based on the nano-scale X-ray computed tomography data replacing typical computer generated microstructure. It is shown that this model can predict the experimental performance of LiFePO 4 (LFP) cathode at different discharge rates more accurate than the conventional homogenous models. The approach employed in this study provides valuable insight into the spatial distribution of lithium -ion inside the real microstructure of LIB electrodes. The inhomogenous microstructure of LFP causes a wider range of physical and electrochemical properties in microscale compared to homogenous models. [ABSTRACT FROM AUTHOR]

An empirical model for commercial lithium-ion batteries is developed based on electrochemical impedance spectroscopy (EIS) tests. An equivalent circuit is established according to EIS test observations at various battery states of charge and temperatures. A Laplace transfer time based model is developed based on the circuit which can predict the battery operating output potential difference in battery electric and plug-in hybrid vehicles at various operating conditions. This model demonstrates up to 6% improvement compared to simple resistance and Thevenin models and is suitable for modeling and on-board controller purposes. Results also show that this model can be used to predict the battery internal resistance obtained from hybrid pulse power characterization (HPPC) tests to within 20 percent, making it suitable for low to medium fidelity powertrain design purposes. In total, this simple battery model can be employed as a real-time model in electrified vehicle battery management systems. [ABSTRACT FROM AUTHOR]

A simplified physics-based model is developed to predict the performance of an LiFePO 4 cathode at various operating and design conditions. Newman's full-order porous-electrode model is simplified using polynomial approximations for electrolyte variables at the electrode-level while a multi-particle model featuring variable solid-state diffusivity is employed at the particle level. The computational time of this reduced-order model is decreased by almost one order of magnitude compared to the full-order model without sacrificing the accuracy of the results. The model is general and can be used to expedite the simulation of any composite electrode with active-material particles of non-uniform properties (e.g., size, contact resistance, material chemistry etc.). In a broader perspective, this model is of practical value for electric vehicle power train simulations and battery management systems. [ABSTRACT FROM AUTHOR]

Highlights: [•] The LIB model is simplified for a range of cell designs and operating conditions. [•] Ragone plots are employed to estimate the accuracy of the simplified model. [•] Diffusion contribution in ion transfer in electrolyte is less significant than the migration. [•] Diffusive ion transfer can be neglected in most LIB designs and operating conditions. [•] Salt concentration gradient can be neglected in some LIB designs and operating conditions. [ABSTRACT FROM AUTHOR]

SUMMARY The effect of physical and chemical properties on the performance of both positive and negative electrodes is studied for lithium-ion (Li-ion) batteries. These properties include the lithium diffusivity in the active electrode material, the electrical conductivity of the electrode, and the reaction rate constant at electrode active sites. The specific energy and power of the cells are determined at various discharge rates for electrodes with different properties. In addition, this study is conducted across various cell design cases. The results reveal that at moderate discharge rates, lithium diffusivity in the active negative-electrode material has the highest impact on cell performance. The specific energy and power of the cell are improved ~11% by increasing the lithium diffusivity in the active negative-electrode material by one order of magnitude. Around 4% improvement in the cell performance is achieved by increasing the reaction rate constant at the active sites of either electrodes by one order of magnitude. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The cathode performance of lithium-ion batteries (LIBs) fabricated from recycled cathode active materials is studied for three scenarios. These scenarios are based on the conditions for separation of different cathode active materials in recycling facilities during the LIB's recycling process. In scenario one, the separation process is performed ideally, and the obtained pure single cathode active material is used to make new LIBs after regeneration. In scenario two, the separation of active materials is performed with efficiencies of less than 100%, which is the actual case in the recycling process. In this scenario, a single cathode active material that contains a little of the other types of cathode active materials is used to make new LIBs after the materials' regeneration. In scenario three, the separation has not been performed during the recycling process. In this scenario, all types of cathode active materials are regenerated together, and a mixture is used to make new LIBs. The studies are performed through modeling and computer simulation, and several experiments are conducted for validation purposes. The cathode active materials that are studied are the five commercially available cathodes made of LiMn2O4 (LMO), LiCoO2 (LCO), LiNixMnyCo(1−x−y)O2 (NMC), LiNixCoyAl(1−x−y)O2 (NCA), and LiFePO4 (LFP). The results indicate that the fabrication of new LIBs with a mixture of cathode active materials is possible when cathode active materials are not ideally separated from each other. However, it is recommended that the separation process is added to the recycling process, at least for the separation of LFP or reducing its amount in the cathode active materials mixture. This is because of the difference of the voltage level of LFP compared to the other studied active materials for cathodes. [ABSTRACT FROM AUTHOR]

• Separation of active materials is added to the LIBs physical recycling method. • Separation of active materials is done using heavy liquids based on Stokes' law. • Separation using heavy liquids is rapid and the recovery efficiency is high. • Separation does not change the active materials morphology and composition. Lithium-ion batteries (LIBs) dominate the industry of rechargeable batteries in recent years due to their advantages, including high energy and power density and relatively long lifespan. Despite these advantages, the disposal of spent LIBs into the ground is harmful to the environment, which needs to be addressed by recycling spent LIBs. The available recycling methods for spent LIBs such as pyrometallurgy and hydrometallurgy focus only on collecting valuable elements from the spent LIBs. The direct physical recycling method may be more economical than the other two methods if the mixed cathode and anode active materials are separated, directly regenerated, and then used to make new LIBs. The first obstacle in this method is the separation of different types of spent active materials that came in the form of micro-sized powder (filter cake). This study aims to separate the mixture of cathode and anode active materials by adopting Stokes' law. The focus is on the physical separation rather than the thermal or chemical separation methods to avoid damaging the morphology and composition of electrode active materials. The proposed mathematical model shows how fast and effectively different electrode materials can be separated by adjusting the heavy liquid density. For validation, several experiments are conducted to separate the cathode active materials (LiCoO 2 , LiFePO 4, LiNi 0.8 Co 0.15 Al 0.05 O 2, LiNi 1/3 Co 1/3 Mn 1/3 O 2 , and LiMn 2 O 4) and the anode active material (Graphite) from each other. Overall, this study shows how rapidly and effectively (high purity) electrode active materials can be separated without damaging the morphology and the composition of electrode active materials. [ABSTRACT FROM AUTHOR]

An efficient fundamental approach for three-dimensional modeling of LiFePO 4 (LFP) battery pouch cells is presented in this paper. First, the standard Newman pseudo two-dimensional (P2D) model is compared with two simplified approaches developed by the authors: a simplified electrochemical multi-particle (SEMP) model, and a homogenous pseudo two-dimensional (HP2D) model. It is shown that the SEMP and HP2D models can predict the operating voltage of LFP half-cells with less than 2.5 % and 1.5 % maximum error, respectively, when compared to the P2D model. It is also shown that the simulation time of these two simplified models are one order of magnitude less than the P2D model, hence, they are then used for three-dimensional modeling of the LFP half-cell. Multiple one-dimensional SEMP models are combined, as a first approach, to form a three-dimensional battery model. It is explained that although this method is adequate for predicting the electrochemical current generation distribution, it may introduce errors in heat generation calculations since it does not consider the electrolyte concentration and potential gradient parallel to the current collectors. Therefore, using the HP2D model, an optimized method is proposed that combines the speed and simplicity of the first approach with three-dimensional simulation of the electrolyte. It is shown that this method is able to predict the mentioned gradients that contribute to the battery heat generation. [ABSTRACT FROM AUTHOR]

The accuracy of state of health (SOH) estimation function in battery management systems is an essential factor for ensuring the safety and reliability of battery systems in electric aircraft. Most common SOH estimation approaches are model-based and work with constant model parameters. However, the model parameters vary by the change in operating temperature and state of charge (SOC). The variation of model parameters has adverse impact on the accuracy of battery state's estimation if they are not updated. In this paper, an accurate online parameter estimation method is proposed for lithium-ion batteries (LIBs) to increase the accuracy of the battery model. A more accurate model for the battery leads to a more accurate SOC and SOH estimation. An adaptive sliding observer is developed to estimate the SOC and capacity based on the proposed parameter estimator. An adaptive SOH estimation scheme is proposed to mitigate the temperature variation effect on the accuracy of the SOH estimation. The experimental results verify the effectiveness of the proposed parameter estimator along with the adaptive sliding observer on achieving accurate estimation of SOC and capacity. The proposed adaptive SOH shows good agreement with experiments by less than 1.3% estimation error at different operating temperature conditions. • An efficient BMS has been designed for electric/hybrid electric aircraft. • An adaptive model for SOC and SOH estimations has been proposed. • Experimental results showed the model error is 1.3% for estimation of SOH. [ABSTRACT FROM AUTHOR]

In this study, synchrotron X-ray nano-computed tomography at Advanced Photon Source in Argonne National Laboratory has been employed to reconstruct real 3D active particle morphology of a LiMn 2 O 4 (LMO) electrode commonly used in lithium-ion batteries (LIBs). For the first time, carbon-doped binder domain (CBD) has been included in the electrode structure as a 108 nm thick uniform layer using image processing technique. With this unique model, stress generated inside four LMO particles with a uniform layer of CBD has been simulated, demonstrating its strong dependence on local morphology (surface concavity and convexity), and the mechanical properties of CBD such as Young’s modulus. Specifically, high levels of stress have been found in vicinity of particle’s center or near surface concave regions, however, much lower than the material failure limits even after discharging at the rate as high as 5C. On the other hand, the stress inside CBD has reached its mechanical limits when discharged at 5C, suggesting that it can potentially lead to failure by plastic deformation. The findings in this study highlight the importance of modeling LIB active particles with CBD and its appropriate compositional design and development to prevent the loss of electrical connectivity of the active particles from the percolated solid network and power losses due to CBD failure. [ABSTRACT FROM AUTHOR]