Battery Cells Research Articles

3DOM Fe/Co-containing perovskites as bifunctional ORR/OER electrocatalysts for a photo-rechargeable zinc battery

Three-dimensionally ordered mesoporous perovskites (La0.8Ba0.2Fe1–xCoxO3–δ (x = 0, 0.2, 0.4)), which are integrated with a silicon photovoltaic cell are prepared. Their overall solar energy conversion and storage efficiency in zinc-ion-based batteries was assessed. The electrocatalytic activities were measured in OER/ORR, while the galvanostatic charge/discharge processes were applied to study battery performance under 1 sun irradiation. The electronic properties of the electrocatalysts were determined by X-ray absorption and UV photoelectron spectroscopies. The importance of controlling the oxidation state of cobalt ions to increase the specific capacity and energy density of the batteries was shown. The ORR activity depends on oxygen vacancies, inferred from the XANES and EXAFS spectra analysis. Their presence is associated with the Co2+/Co3+ ratio which controls the beneficial eg orbitals occupancy via the high spin d7 electron configuration. Herein, we report an overall energy conversion efficiency of 12.6 % for the PV-integrated La0.8Ba0.2Fe0.8Co0.2O3–δ photo-rechargeable battery cell.

A closer look at lithium-ion batteries in E-waste and the potential for a universal hydrometallurgical recycling process

The demand for lithium-ion batteries (LiBs) is rising, resulting in a growing need to recycle the critical raw materials (CRMs) which they contain. Typically, all spent LiBs from consumer electronics end up in a single waste stream that is processed to produce black mass (BM) for further recovery. It is desired to design a recycling process that can deal with a mixture of LiBs. Hence, this study investigates the structure and composition of battery modules in common appliances such as laptops, power banks, smart watches, wireless earphones and mobile phones. The battery cells in the module were disassembled into cell casing, cathode, anode and separator. Then, the cathode active materials (CAMs) were characterized in detail with XRD-, SEM-, EDX- and ICP-OES-analysis. No direct link was found between the chemistry of the active materials (NMC, LCO, LMO, LFP etc.) and the application. Various BM samples were submitted to a leaching procedure (2 M H2SO4, 50 °C, 2 h, 60 g BM/L) with varying concentration (0–4 vol%) of H2O2 to study the influence of their chemical composition on the dissolution of Li, Ni, Mn and Co. Only a part of the BMs dissolved completely at 4 vol% H2O2, which was attributed to the oxidation state of the transition metals (TMs). Exact determination of H2O2 consumption by redox titration confirmed this hypothesis.

A comparison of multi-source power supply systems for autonomous marine vehicles: The SWAMP case study

Extensive research on zero-emissions autonomous surface vehicles has been recently carried out, aiming at increasing autonomy. Due to their small size, unmanned vehicles present unique difficulties in terms of weight and dimensions when powering the vehicle with renewable energy sources. In this paper, photovoltaic source, fuel cell and Li-ion battery multi-source configurations are proposed, demonstrating by physical layout and simulation results the feasibility of the prototype, compliant with strict constraints of the vehicle under test. The energy system model of the vehicle under test is implemented in MATLAB/Simulink. A comparison of multi-source energy system configurations is proposed and validated by simulation results in terms of endurance, weight and size. If compared with the original battery-powered vehicle, as shown by comparing simulation results, the endurance is doubled, extended up to 12 h on the most favorable day of the year. The solution even complies with payload and physical dimensions constraints.

Performance evaluation of an automatic resonant switched capacitor-based voltage balancing circuits for series connected batteries

Electrical energy storage (EES) plays a crucial role in various power applications. Voltage imbalance is a common issue that can negatively affect the efficiency, reliability, and safety of EESs. Several types of voltage balancing (VB) circuits have been proposed in much of the literature. Among these VB circuits, switched capacitor (SC)-based circuits have attracted significant interest due to their efficiency, cost-effectiveness, compact size, and ease of control, but their balancing performance is not yet satisfactory. As a result, structural modifications in SC-based circuits have been widely proposed to improve balancing performance. However, not all of these circuit structures have been implemented into a resonant switched capacitor (RSC)-based voltage balancing, which has higher efficiency. Hence, this study aims to assess the efficiency of RSC-based VB circuits by conducting analog simulation using the Matlab Simulink software. This research evaluates the performance of the VB circuit not only in terms of its speed and efficiency, but also in terms of its energy distribution. The results show that the delta structure is the fastest in terms of balancing speed when completing the balancing process, followed by the mesh structure and the parallel structure. The best energy distribution is produced by a parallel structure, as indicated by the change in voltage of all battery cells always moving towards a convergent value, regardless of the variations in initial imbalance conditions. Meanwhile, other circuit structures distribute energy randomly, allowing the voltage of the battery cells to change not directly towards a convergent value. Lastly, the paper summarizes the balancing speed, efficiency, circuit complexity, and quality of energy distribution.

From Powder to Pouch Cell: Setting up a Sodium‐Ion Battery Reference System Based on Na3V2(PO4)3/C and Hard Carbon

At the research level, novel active materials for batteries are synthesised on a small scale, fabricated into electrodes and electrochemically characterised using each group’s established process due to the lack of standards. Recently, eminent researchers have criticised the implementation of e.g. low active material contents/electrode loadings, the use of research‐type battery cell constructions, or the lack of statistically relevant data, resulting in overstated data and thus giving misleading predictions of the key performance indicators of new battery technologies. Here, we report on the establishment of a reference system for the development of sodium‐ion batteries. Electrodes are fabricated under relevant conditions using 9.5 mg/cm² self‐synthesised Na3V2(PO4)3/C cathode active material and 3.6 mg/cm² commercially available hard carbon anode active material. It is found that different types of battery cells are more or less suitable for half‐ and/ or full‐cell testing, resulting in ir/reproducible or underestimated active material capacities. Furthermore, the influence of electrode overhang, which is relevant for upscaling, is evaluated. The demonstrator cell (TRL 4‐5) has been further characterised providing measured data on the power/energy density and thermal behaviour during rate testing up to 15 C and projections are made for its practical limits.

Comparative Cost Modeling of Battery Cell Formats and Chemistries on a Large Production Scale

As lithium-ion batteries increasingly become a cornerstone of the automotive sector, the importance of efficient and cost-effective battery production has become paramount. Even though electric vehicle battery cells are produced in three different geometries—cylindrical, prismatic, and pouch—no specific model exists to compare the manufacturing costs of producing cells with different geometries but similar performances. In this paper, we present a process-based cost model with a cell design functionality which enables design and manufacturing cost prediction of user-defined battery cells.

17-Cell battery monitoring analog front end with high sampling accuracy for battery pack applications

Battery management system (BMS) is a critical aspect to ensure the safe, reliable operation of lithium ion batteries for battery pack applications. Although some battery pack monitoring schemes have increased the number of measurable channels in a chip for higher voltage battery packs, the issue of accuracy caused by the common mode voltage difference in each unit of series battery pack remains unsolved. A high voltage multiplexer of 17-cell battery monitoring analog front end (AFE) is adopted to acquire each cell voltage for accurate monitoring. Besides, a current compensation scheme is proposed to tackle the current leakage in each channel to further improve the acquisition accuracy. The proposed scheme is implemented in 0.18 μm high-voltage BCD process, and occupies a die size of 2.92 × 3.23 mm2. The experimental results reveal that the sensing error of 17 battery cells is within ±2 mV under the input cell voltage from 1 to 5V.

CFD investigation of pouchtype lithium-ion battery

PurposeIn the dynamic realm of energy storage, lithium-ion batteries stand out as a frontrunner, powering a myriad of devices from smartphones to electric vehicles. However, efficient heat management is crucial for ensuring the longevity and safety of these batteries. This paper aims to delve into the process of lithium-ion battery heat management systems, exploring how cutting-edge technologies are used to regulate temperature and optimize performance. In addition, computational fluid dynamics (CFD) studies take center stage, offering insights into the intricate thermal dynamics within these powerhouses.Design/methodology/approachIn this study, thermal behavior of pouch type lithium-ion battery cell has been investigated by using CFD method. Result of different discharge rates have been evaluated by using multi-scale multi-dimensional (MSMD) battery model. By using MSMD Model 0.5C, 1C, 2C, 3C and 5C discharge rates are compared in equivalent circuit model (ECM) and NTGK empirical models by monitoring averaged surface temperature on battery body wall. In addition, on NTGK model, air cooling effect has been studied with the 0.1 m/s, 0.2 m/s and 0.5 m/s air, velocities.FindingsResults shows that higher discharge rate causes higher temperature on battery zones and air cooling is effective to obtain the lower zone temperatures. Also, ECM model gives higher temperature than NTGK model on battery zone.Originality/valueWhen the literature is evaluated, comparison of the models used in battery cooling (ECM and NTGK) has never been done before. Within the scope of this study, model comparison was made. At the same time, the time step has always been ignored in the literature. In this study, both time step and forced convection conditions were considered when comparing the models.

Thermal management of battery cell module using a hybrid nanofluid filled inverted right-angled porous triangular cavity through natural convection

Thermal management of battery cell module using a hybrid nanofluid filled inverted right-angled porous triangular cavity through natural convection

Photonic Synthesis and Coating of High‐Entropy Oxide on Layered Ni‐Rich Cathode Particles

High‐entropy materials have drawn much attention as battery materials due to their distinctive properties. Lithiated high‐entropy oxide (Li0.33(MgCoNiCuZn)0.67O, LiHEO) exhibits both high lithium‐ion and electronic conductivity, making it a potential coating material for layered Ni‐rich oxide cathodes (Li1+x(Ni1−y−zCoyMnz)1−xO2, NCM or NMC) in conventional Li‐ion battery cells; however, high‐temperature synthesis limits its application. Therefore, a photonic curing strategy is used for synthesizing LiHEO and the non‐lithiated form (denoted as high‐entropy oxide [HEO]), and nanoscale coatings are successfully produced on LiNi0.85Co0.1Mn0.05O2 (NCM851005) particles. To one's knowledge, this is the first report on particle coating with high‐entropy materials using photonic curing. NCM851005 with LiHEO‐modified surface shows good cycling stability, with a capacity retention of 97% at 1 C rate after 200 cycles. The improvement in electrochemical performance is attributed to the conformal coating that prevents structural changes caused by the reaction between cathode material and liquid electrolyte. Compared to bare NCM851005, the coated material shows a significantly reduced tendency for intergranular cracking, successfully preventing electrolyte penetration and suppressing side reactions. Overall, photonic curing presents a novel cost‐ and energy‐efficient synthesis and coating procedure that paves the way for surface modification of any heat‐sensitive material for a wide range of applications.

A Novel Voltage-Abnormal Cell Detection Method for Lithium-Ion Battery Mass Production Based on Data-Driven Model with Multi-Source Time Series Data

Before leaving the factory, lithium-ion battery (LIB) cells are screened to exclude voltage-abnormal cells, which can increase the fault rate, troubleshooting difficulty, and degrade pack performance. However, the time interval to obtain the detection results through the existing voltage-abnormal cell method is too long, which can seriously affect production efficiency and delay shipment, especially in the mass production of LIBs when facing a large number of time-critical orders. In this paper, we propose a data-driven voltage-abnormal cell detection method, using a fast model with simple architecture, which can detect voltage-abnormal cells based on the multi-source time series data of the LIB without a time interval. Firstly, our method transforms the different source data of a cell into a multi-source time series data representation and utilizes a recurrent-based data embedding to model the relation within it. Then, a simplified MobileNet is used to extract hidden feature from the embedded data. Finally, we detect the voltage-abnormal cells according to the hidden feature with a cell classification head. The experiment results show that the accuracy and average running time of our model on the voltage-abnormal cell detection task is 95.42% and 0.0509 ms per sample, which is a considerable improvement over existing methods.

Revealing the materials, design, and performance of Ni-rich LiNi1-x-yCoxMnyO2/graphite pouch cells

Among lithium-ion batteries (LIBs), Ni-rich LiNi1-x-yCoxMnyO2/Graphite batteries hold a dominant position in electric vehicles due to high energy density, good cycling stability, and low content of Co element. In this work, Ni-rich LiNi1-x-yCoxMnyO2 (LiNi0.83Co0.07Mn0.10O2, NCM83)/Graphite pouch cells with a capacity of around 2.1 Ah are designed and manufactured. The structure and micromorphology of NCM83 as well as graphite are revealed. The XRD Rietveld refinement method clarifies the lattice parameters of NCM83. The PE separator modified by Al2O3 and PVDF (PE/Al2O3/PVDF) is used in the cells. The design parameters, formation, and aging processes are disclosed as well. Charge-discharge tests demonstrate that the NCM83/Graphite pouch cells have good electrochemical performance. Notably, the cell delivers an initial discharge capacity of 2.158 Ah at 1 A and 25 °C, and retains a high reversible discharge capacity of 1.715 Ah after 500 cycles with a capacity retention of close to 80 %. Additionally, the polarization characteristics during charging and discharging are discussed in detail, demonstrating that a good linear relationship exists between polarization voltage and cycle number. This work systematically reveals the materials, and design technology of NCM83/Graphite battery cells and helps deepen the understanding of commercial LIBs based on Ni-rich LiNi1-x-yCoxMnyO2 cathode materials.

Polyester‐Polycarbonate Polymer Electrolytes Beyond LiFePO4: Influence of Lithium Salt and Applied Potential Range

AbstractRechargeable polymer‐based solid‐state batteries with metallic lithium anodes and LiNixMnyCo1−x−yO2 (NMC)‐based cathodes promise safer high‐energy‐density storage solutions than existing lithium‐ion batteries, but have shown challenging to realize. The failure mechanisms that have been suggested for these battery cells have mostly been related to the use of a metallic lithium anode and formation of dendrites during cycling. Here, we approach the issue of using solid polymer electrolytes (SPEs) vs. NMC cathodes by employing a range of materials based on poly(ϵ‐caprolactone‐co‐trimethylene carbonate) (PCL‐PTMC) with different salts under various cycling conditions. It is seen that although the ionic conductivity of the electrolyte can be improved by exchanging the lithium salt, it does not immediately correlate to better cycling performance. However, increasing the temperature during battery cycling to improve the ion transport kinetics lowers the polarization of the battery cell and full capacity can be achieved at an upper voltage cut‐off that is appropriate for the polymer electrolyte. For these electrolytes, the limit is demonstrated to be 4.4 V vs. Li+/Li, and cycling with NMC‐111 cathodes is thereby possible provided that the upper cut‐off is limited to below this limit.

Rational design of dual-ion doped cobalt-free Li-rich cathode materials for enhanced cycle stability of lithium-ion pouch cell batteries.

The synergistic effect of single-crystal structure and dual doping in Li-rich cobalt-free cathode materials was thoroughly investigated. Lithium-ion pouch cells employing Sb/Sn doped Li1.2Mn0.6Ni0.2O2 and graphite exhibited a specific capacity of 191.01 mA h g-1 at 1C rate and exceptionally stable performance upon cycling, with capacity retention of 87.24% of their initial capacity after 250 cycles at 1C rate. The strategic combination of morphology manipulation and dual ion doping has markedly diminished cation mixing and expanded the Li interstitial sites within the cathode lattice. This work offers significant insights into the mechanisms responsible for the structural decline of Li-rich cobalt-free cathodes, emphasizing the importance of stabilizing the cathode lattice structure at high potential. These findings suggest promising potential for this material to meet the demanding energy density criteria for electric vehicles. Finally, this research provides practical strategies for effectively implementing high-voltage cobalt-free cathodes, offering valuable guidance for future applications.

Characteristics of phosphorus‑nitrogen based flame-retardant monomers for UV-curable coatings on battery PET pouches

In this study, photocurable monomers containing phosphorus–nitrogen groups were employed alongside UV curing technology to develop flame-retardant (FR) coatings pouch-type battery cells made from polyethylene terephthalate (PET). Three different monomers were synthesized: a phosphorus-containing urethane acrylate monomer (DUPPO), a phosphorus–nitrogen-containing urethane acrylate monomer (DA-Pi-U), and a phosphazene-containing phenyl methacrylate crosslinker (CP-PMA). These monomers, recognized for their flame-retardant properties, were utilized in binary and ternary coating formulations that were effectively cured via a UV-curing process. The molecular architectures of the synthesized monomers were verified through 1H and 31P nuclear magnetic resonance spectroscopy. The rheological curing behavior of the coating solutions was assessed using an oscillatory rheometer. In addition, the reactivity of the FR coating system was examined via Fourier transform infrared spectroscopy. The thermal and flame-retardant characteristics of the FR coatings were confirmed through thermogravimetric analysis, Raman spectroscopy, limiting oxygen index measurements, and scanning electron microscopy. The ternary FR coating system with CP-PMA exhibited superior thermal stability, flame retardancy, crosslinking density, and mechanical robustness, making it suitable for PET pouches. Furthermore, optimal coating conditions for the slot coating process were determined using a viscocapillary model, enhancing practical applicability in industrial settings.

Reinforcement learning for battery energy management: A new balancing approach for Li-ion battery packs

This study investigates the challenge of cell balancing in battery management systems (BMS) for lithium-ion batteries. Effective cell balancing is crucial for maximizing the usable capacity and lifespan of battery packs, which is essential for the widespread adoption of electric vehicles and the reduction of greenhouse gas emissions. A novel deep reinforcement learning (deep RL) approach is proposed for passive balancing with switched shunt resistors. Notable deep RL algorithms capable of handling discrete actions, such as Trust Region Policy Optimization (TRPO), Proximal Policy Optimization (PPO), Deep Q-Network (DQN), Augmented Random Search (ARS), and Asynchronous Advantage Actor Critic (A3C), are investigated. TRPO demonstrates superior performance compared to other deep RL algorithms and rule-based methods in both charging and discharging scenarios without requiring fine-tuning, optimizing the balance between cell balancing and switch changes. It achieves up to 16.8% improvement in battery pack capacity, 69.4% reduction in state-of-charge variance among cells, and 40.4% decrease in the number of switching operations in simulation results for five li-ion cells connected in series.The study introduces an innovative application of deep RL for passive balancing, a comprehensive battery cell modeling technique, and a tailored multi-objective reward function that balances cell balancing and switching costs. This work represents a significant advancement in applying deep RL to battery management systems, providing a framework for further research and practical implementation in energy storage systems.

Fault diagnosis method for lithium-ion batteries based on the combination of voltage prediction and Z-score

ABSTRACT Safety accidents in new energy electric vehicles caused by lithium-ion battery failures occur frequently, and the timely and accurate diagnosis of failures in battery packs is crucial. Voltage, as one of the primary characterization parameters of lithium-ion battery malfunctions, is widely utilized in fault diagnosis. This article proposes a lithium-ion battery fault diagnosis method Fault diagnosis method based on the combination of voltage prediction and Z-score. Firstly, the stable trend component is extracted from the battery voltage data using variational mode decomposition, which avoids the influence of noisy signals and random perturbations to the greatest extent. Subsequently, a TCN-BiLSTM-attention model is designed to estimate the average voltage of the battery under normal conditions. Finally, the residuals between the estimated and individual cell voltages are calculated, and the Z-score is utilized to locate and judge whether the battery is caused by the occurrence of a fault. Through verification with real vehicle data and experimental data, the proposed method effectively identifies abnormal battery cells. Compared to the correlation coefficient method, this approach exhibits superior applicability.

Solutions for decarbonising urban bus transport: a life cycle case study in Saudi Arabia

With heavy reliance on fossil fuels, countries like Saudi Arabia face challenges in reducing carbon emissions from urban bus transportation. Herein, we address the gaps in evaluating proton-exchange membrane fuel cell buses and develop a globally relevant life-cycle assessment model using Saudi Arabia as a case study. We consider various bus propulsion technologies, including fuel cell buses powered by grey and blue hydrogen, battery electric buses, and diesel engines, and include the shipping phase, air conditioning load, and refuelling infrastructure. The assessment illustrates fuel cell buses using blue hydrogen can reduce emissions by 53.6% compared to diesel buses, despite a 19.5% increase in energy use from carbon capture and storage systems. Battery electric buses are affected by the energy mix and battery manufacturing, so only cut emissions by 16.9%. Sensitivity analysis shows climate benefits depend on energy sources and efficiencies of carbon capture and hydrogen production. By 2030, grey and blue hydrogen-powered fuel cell buses and battery electric buses are projected to reduce carbon emissions by 19.3%, 33.4%, and 51% respectively, compared to their 2022 levels. Fully renewable-powered battery electric buses potentially achieve up to 89.6% reduction. However, fuel cell buses consistently exhibit lower environmental burdens compared to battery electric buses.

Incoming Inspection of Lithium‐Ion Batteries Based on Multi‐cell Testing

Incoming inspections of battery cells prior to module assembly help to ensure the quality of the battery system and prevent the installation of anomalous cells. Depending on the area of application, identifying deviations in the electrical behavior of the battery cells under test can be essential for downstream assembly processes like cell matching and algorithm adaptations of the battery management software. In this work, the use of a multi‐cell testing procedure involving differential voltage analysis, incremental capacity analysis, direct current internal resistance tests, and electrochemical impedance spectroscopy is investigated to reveal differences in cell properties and identify anomalous cells while economizing on the required cell test channels. The results obtained from 20 model‐identical 21700 cylindrical cells from four different batches demonstrate that this methodology can detect material variations, such as differing silicon and graphite content, which are not disclosed by the supplier or indicated in the data sheet. A teardown with elemental analysis of two cells from different batches is carried out as verification. Finally, prospects for potential application scenarios and raw measurement data are provided.

Thermal properties of cooling tube battery pack embedded with triangle umbrella-shaped cellular structure

To further enhance heat dissipation efficiency and temperature uniformity of battery pack, a novel cooling tube battery pack embedded with triangle umbrella-shaped cellular structure (TUCS) with negative Poisson’s ratio (NPR) is proposed. Firstly, heat generation models of battery cell are derived and temperature rise tests are conducted to verify the accuracy of heat generation theory and simulation models of lithium battery cell. Meanwhile, cooling tube battery pack with bidirectional serpentine tube is established, and the influences of different flow rates and directions of coolant, diameter of cooling tube and spoiler columns on heat dissipation efficiency of cooling tube battery pack are investigated through simulation analysis. Moreover, relative density of TUCS is calculated and thermal conductivity expressions of TUCS are derived by Maxwell-Eucken model. Subsequently, the embedded TUCS is taken as the medium to conduct heat between cooling tubes and battery modules. Then, the influences of structural parameters of TUCS on heat dissipation efficiency of cooling tube battery pack are determined. Further, the optimal TUCS with the needs of high heat dissipation efficiency, superior temperature uniformity and more lightweight space of battery pack is achieved. Similarly, density gradient of the TUCS can be defined and impacts of TUCS with density gradient distribution on thermal performances of battery pack are investigated. Eventually, the highest temperature and maximum temperature difference of the optimal cooling tube battery pack, cooling tube battery pack embedded with the optimal TUCS and cooling tube battery pack embedded with the optimal gradient distribution TUCS are obtained. Compared with the optimal cooling tube battery pack, the highest temperatures of another two cooling tube battery packs decrease 16.50 % and 16.48 %, and the corresponding maximum temperature differences decrease 93.06 % and 93.20 %, respectively. Meanwhile, the highest temperature and maximum temperature difference of another two battery modules are 303.76 K and 3.76 K at 5C discharge rate. The proposed cooling tube battery pack with the optimal gradient distribution TUCS can decrease the highest temperature and maximum temperature difference effectively.