Battery System Research Articles

SOLAR BASED WHEEL CHAIR FOR DISABLED

The Solar Based Wheelchair for Disabled (SBWCD) is a groundbreaking project aimed at enhancing mobility and independence for individuals with disabilities by harnessing the power of solar energy. Traditional wheelchairs often rely on manual propulsion or battery-powered motors, which can be limiting in terms of range, accessibility to charging stations, and environmental impact. In response to these challenges, the SBWCD project introduces a novel approach by integrating solar panels into the design of wheelchairs to harness solar energy and convert it into electrical power for propulsion. This innovative solution offers numerous benefits, including extended range, reduced reliance on grid electricity, and decreased carbon footprint. The SBWCD features a lightweight and durable frame equipped with high-efficiency solar panels mounted on the backrest and armrests, maximizing exposure to sunlight while maintaining user comfort and ergonomics. The solar panels are connected to an onboard battery system, which stores excess energy generated during daylight hours for use during periods of low sunlight or at night. This hybrid power system ensures continuous operation of the wheelchair regardless of environmental conditions, providing users with greater autonomy and freedom of movement. Moreover, the SBWCD is designed with user-centric features and accessibility in mind. Adjustable seating, armrests, and footrests accommodate users of varying sizes and preferences, while ergonomic controls and intuitive interfaces ensure ease of operation for individuals with limited mobility or dexterity. Additionally, safety features such as anti-tip mechanisms, seat belts, and obstacle detection systems enhance user confidence and mitigate risks associated with wheelchair use in diverse environments. In summary, the Solar Based Wheelchair for Disabled (SBWCD) project represents a significant advancement in assistive technology, offering a sustainable and user-friendly solution for individuals with disabilities. By harnessing the abundant and renewable energy of the sun, SBWCD empowers users to navigate their surroundings with greater independence, efficiency, and environmental consciousness. As the demand for accessible and eco-friendly mobility solutions continues to grow, the SBWCD project serves as a beacon of innovation and inclusivity in the field of assistive technology.

DEVELOPMENT OF ULTRA CAPACITOR BASED REGENERATIVE BRAKING SYSTEM FOR ELECTRIC VEHICLES

Regenerative braking is a technique for converting a moving vehicle's kinetic energy into usable form while slowing it down. When an automobile brakes violently, it usually emits heat. If we could conserve energy rather than waste it, that would be amazing, right? That's where regenerative braking technology comes in handy, especially for electric vehicles. It stores the wasted energy in a battery or ultra-capacitor, so it can be used later to start or accelerate the vehicle. In our project, we looked at how effective regenerative braking is during both braking and starting modes. We compared starting the motor with a battery, ultra-capacitor, or a combination of both (HESS), and also analyzed how storing energy during braking works with these systems. Although not all of the regenerated energy is reinvested in the battery, the motor acts as a generator, charging the vehicle's battery. To move the vehicle forward, regenerative braking uses the kinetic energy it temporarily stores during deceleration. We used a lithium-ion battery and ultra-capacitor module energy storage system coupled to a BLDC motor via a converter. These brakes help batteries last longer without needing to be charged externally. They enable efficient power transfer during regenerative braking and acceleration. Our project discusses whether regenerative braking increases or decreases efficiency. of state of charge of battery and ultra- capacitor when starting and braking applied in discharging(in running of motor) and charging(in regenerative braking of motor). And also BLDC motor speed control in starting and braking mode. The model is simulated using MATLAB Simulink software. Keywords: Regenerative braking, kinetic energy, electric vehicles, energy storage, battery, ultra-capacitor, starting mode, braking mode, Hybrid Energy Storage System (HESS), efficiency, motor generator

Employing Graph Neural Networks for Predicting Electrode Average Voltages and Screening High-Voltage Sodium Cathode Materials.

For many years, humans have been relentlessly focused on enhancing battery longevity and boosting energy storage capacities. The performance and durability of a battery depend significantly on the material used for its electrodes. In this context, merging machine learning with density functional theory (DFT) calculations has emerged as a pivotal approach to advancing the exploration of battery crystal structures. We present a new method that combines a graph convolutional neural network (GNN) with a Transformer convolutional layer, which we call Transformer-GNN. To underscore its efficacy, we benchmarked Transformer-GNN against three established statistical machine learning models: Support Vector Machine, Random Forest, and XGBoost. We also developed a standard GNN, which we refer to as Basic-GNN. Additionally, we compared Basic-GNN with Transformer-GNN to highlight the improvements brought about by incorporating the Transformer convolutional layer. The Transformer-GNN model outperforms the other models, achieving the highest R2 value of 0.82 and the lowest mean squared error of 0.3161. Our findings demonstrate that the Transformer-GNN can profoundly understand battery crystal structures, thus forging the path toward more sophisticated and durable battery systems. Leveraging the GNN model's voltage predictions in tandem with the capacity data sourced from the database, we screened and pinpointed Na(NiO2)2 as a high-voltage (higher than 5 V), high-capacity sodium cathode material. We conducted DFT calculations on Na(NiO2)2 and revealed the migration mechanism of the Na ions.

Structural optimization of thermal management system for bionic liquid cold battery based on fuzzy grey correlation analysis

Structural optimization of thermal management system for bionic liquid cold battery based on fuzzy grey correlation analysis

Improved rule-based power distribution algorithm for hybrid battery storage systems and real-world validation

Large-scale battery energy storage systems (BESS) can serve many applications and are already widely used for grid services. The rapidly growing BESS market and the recent interest in their deployment accentuate the need for safe, reliable, and highly available energy management systems (EMS) for automated control. However, the EMS and their integrated power distribution algorithms (PDA) can still be optimized to adapt various characteristics of the BESS. This study investigates a new version of a PDA with a particular focus on battery aging and system efficiency. The rule-based PDA has been validated on a 6 MW/7.5 MWh BESS system with five battery technologies providing frequency containment reserve to the German power grid. The results underline the PDA's capability to exploit the individual strengths of each battery technology. The PDA sets objectives for the state of charge, energy throughput, and power of the batteries to extend battery life. The distribution of energy throughputs among batteries can be selected in advance through the new implementation of the PDA. At the same time, the inverters are significantly less often activated and used in the optimal efficiency range, increasing the overall system efficiency to approximately 82 %. The optimized switching behavior leads to less frequent power switching between individual battery units and longer phases with more constant power. In addition, the operational efficiency of BESS can be improved by the choice of battery technology and the overall system layout on the hardware side. The improvements on the software side are only possible by increasing the overall power requests through multi-use operation by about 6 % compared to our benchmark test. The results can be used by BESS operators to increase operational profits due to longer battery life and fewer efficiency losses.

A Robust Model Order Reduction Scheme for Lithium-Ion Batteries in Control-Oriented Vehicle Models

The role of batteries in electrification of vehicles is eminent; thus, a dynamic model that represents the physics-based phenomena of the battery system at a minimum computational cost is essential in the model-based design of electrified vehicle control systems. Furthermore, robustness of the reduced-order battery model when maintaining the dominant physics-based phenomena governing the dynamic behavior of the battery system is crucial. Characterization of the power signal applied to the lithium-ion battery in the energy management controller of a plug-in hybrid electric vehicle shows that there is a dominant frequency range in the input signal to the battery. This key feature can be considered as a basis to construct a reduced-order model in which the training input is different from the original power signal. The original idea in this paper is to generate the training input by applying a low-pass filter to the white-noise random signal to maintain the same dominant frequency range observed in the original power signal. Response of the reduced-order model, constructed using the proper orthogonal decomposition, compared to the high-fidelity battery model shows promising results; a maximum relative error of 1% was obtained for the battery state of charge while simulation time was reduced by 42.9%.

A comparative study on the effects of multi-walled carbon nanotubes and graphene nanoplates incorporated for improved thermal conductivity and dielectric properties of polyvinyl chloride

In the present work, the improvement in the thermal conductivity and dielectric behavior in the frequency range of 0.025–5 MHz of polyvinyl chloride (PVC) films incorporated with graphene nanoplates (GNs) and multi-walled carbon nanotubes (CNTs) were investigated. The neat PVC and PVC composites consisting of different filler ratios of 0.25, 0.5, 0.75, and 1 wt% were synthesized using the casting technique. The increase in the concentration of GNs or CNTs up to 0.75 wt% enhanced the dielectric constant, ac conductivity, q-factor, F-factor, thermal conductivity, and total impedance of PVC composites. The values of the investigated parameters are slightly higher for PVC-CNTs composites compared to PVC-GNs composites. A further increase in concentration to 1 wt% reduces these parameters, but still more than PVC consisting of 0.5 wt% fillers. The mechanism of correlated barrier hopping (CBH) could be successfully used to describe the AC electrical conductivity of both PVC-GNs and PVC-CNTs composites thin films. Furthermore, the glass transition and decomposition temperatures were determined and found to be dependent on the filler ratio and type, and the thermal stability was increased after adding the GNs or CNTs nanofillers. These findings have drawn special attention to developing PVC composites that can be used in various industrial fields including flexible and wearable technologies, power devices, supercapacitors, electric vehicle battery systems, and aerospace components.

Sulfur Encapsulation into Carbon Nanospheres as an Effective Technique to Limit Sulfide Dissolution and Extend the Cycle Life of Lithium–Sulfur Batteries

Sulfur Encapsulation into Carbon Nanospheres as an Effective Technique to Limit Sulfide Dissolution and Extend the Cycle Life of Lithium–Sulfur Batteries

Performance analysis of drone sqadron optimisation based MPPT controller for grid implemented PV battery system under partially shaded conditions

Performance analysis of drone sqadron optimisation based MPPT controller for grid implemented PV battery system under partially shaded conditions

A finite‐state machine‐based control design for thermal and state‐of‐charge balancing of lithium iron phosphate battery using flyback converters

AbstractBattery cell balancing plays a vital role in maximizing the performance of the battery system by enhancing battery system capacity and prolonging the battery system life expectancy. Active cell balancing using power converters is a promising approach to maintaining uniform state of charges (SoCs) and temperatures across battery cells. The SoC balancing function in the battery management system (BMS) increases the battery pack capacity, and the temperature balancing function mitigates variations in the aging of battery cells due to unbalanced temperatures. In this work, a finite‐state machine‐based control design is proposed for lithium iron phosphate (LFP) battery cells in series to balance SoCs and temperatures using flyback converters. The primary objective of this design is to ensure balanced SoCs by the end of the charging session while mitigating the temperature imbalance during the charging process. To achieve the SoC and temperature balancing functions using the same balancing circuits, a finite‐state machine control design decides on the operating mode, and a balancing strategy balances either temperature or SoC depending on the operating mode. The proposed control design has the advantages of low computational burden, simple implementation compared to the optimization‐based controller found in the literature, and the proposed balancing strategy offers faster balancing speed compared to conventional methods. The effectiveness of the proposed strategy is validated on battery cell RC models in series with unbalanced SoCs and temperatures.

Nanodiamond‐Assisted High Performance Lithium and Sodium Ions Co‐Storage

While lithium resources are scarce for high energy‐dense lithium‐ion batteries (LIBs), sodium‐ion batteries (SIBs), serving as an alternative, inherently suffer from low capacity and the high‐cost use of non‐graphite anodes. Combining Li‐ and Na‐ions within a single battery system is expected to mitigate the shortcomings of both systems while leveraging their respective advantages. In this study, we developed and assembled a nanodiamonds (NDs)‐assisted co‐Li/Na‐ion battery (ND–LSIB). This innovative battery system comprised a commercial graphite anode, an ND‐modified polypropylene (DPP) separator, a hybrid lithium/sodium‐based electrolyte, and a cathode. It is theoretically and experimentally demonstrated that the ND/Li co‐insertion can serve as an ion‐drill opening graphite layers and reconstructing graphite anodes into few‐layered graphene with expanding interlayer space, achieving highly efficient Li/Na storage and the theoretical maximum of LiC6 for Li storage in graphite. In addition, ND is helpful for creating a LiF‐/NaF‐rich hybrid solid electrolyte interface with improved ionic mobility, mechanical strength, and reversibility. Consequently, ND–LSIBs have higher specific capacities ~1.4 times the theoretical value of LIBs and show long‐term cycling stability. This study proposes and realizes the concept of Li/Na co‐storage in one ion battery with compatible high‐performance, cost‐effectiveness, and industrial prospects.

A Polysulfides‐Defensive, Dendrite‐Suppressed, and Flame‐Retardant Separator with Lean Electrolyte for Room Temperature Sodium–Sulfur Batteries

AbstractThe dissolution/shuttling of sodium polysulfides, coupled with sodium dendrites growth, severely compromises the lifespan and stability of room temperature sodium–sulfur (RT Na–S) batteries. Herein, it proposes employing a functionalized porous ZIF‐based membrane (PZM) to address these two challenges. First, the metal ions embedded within the zeolitic imidazolate framework chemically bind with polysulfide anions, curtailing their detrimental shuttling. Second, the tailored porous structure of the membrane ensures a selective and uniform pathway for sodium ions, significantly reducing non‐uniform deposition and curbing dendritic sodium growth. Third, the intrinsically non‐combustible nature of the ZIF‐based membrane acts as a fortification against thermal outbursts and electrolyte decomposition. Implementing this polysulfide‐resistant, dendrite‐inhibiting and flame‐retardant PZM with a standard S/C cathode leads to the creation of a robust separator with lean electrolyte RT Na–S battery. This configuration may impart a novel perspective for the advancement and enhancement of RT Na–S battery systems.

Design and Implementation of an Anti-Explosion System for Electric Vehicles Batteries

This research paper investigates the development and implementation of an innovative anti-explosion system designed to control the temperature of electric vehicles (EVs) during operation and parking. The system is designed to improve safety and efficiency by preventing overheating and minimizing the risk of thermal disturbances. This paper also outlines the significance and rising appeal of electric vehicles and explains the need for efficient cooling systems in electric vehicles to maintain optimal performance and safety. It introduces the concept of an explosion-proof cooling system and its potential benefits.

Vanadium redox flow battery: Characteristics and application

Renewable energy such as solar energy and wind energy will enter a new period of development. However, the output power of photovoltaic power generation has great randomness. In order to ensure the normal operation of the whole photovoltaic power generation system, it is particularly important to introduce smooth power dynamics of energy storage system (ESS) to ensure electrical stability. As an energy storage device, flow batteries will develop in the direction of large-scale and modularization in the future. The flow battery system can easily realize computer automatic control and is an ideal smart battery. In addition, the combination of flow batteries with photovoltaic cells, wind power stations, tidal power stations, biogas power stations and other renewable energy systems is an important category and content in developing the application fields of flow batteries. As a new type of green battery, Vanadium Redox Flow Battery (VRFB) has the advantages of flexible scale, good charge and discharge performance and long life. It is suitable for large-scale electric energy storage and has attracted wide attention in recent years. In this paper, the characteristics and applications of liquid flow battery and VRFB are summarized. This paper starts from introducing ESS, analyzing several types of flow batteries, and finally focusing on VRFB to analyze its technical characteristics and application market.

Impact of annealing on the resistance of Li3PO4 electrolyte–LiNi0.5Mn1.5O4 electrode interfaces

The operation of solid-state Li batteries, which are promising power supplies for portable electronic devices and electric vehicles, is accompanied by heating. Therefore, investigating the thermal stability of battery systems is essential. In this study, we report the impact of annealing on the interface of a Li3PO4 electrolyte and LiNi0.5Mn1.5O4 electrode in thin-film batteries. The batteries with the interface annealed at 200 °C show low Li3PO4–LiNi0.5Mn1.5O4 interface resistance of 7.2 Ω cm2. Furthermore, the batteries exhibit stable charge–discharge characteristics with high current density up to 1170 μA cm−2, similar to those of batteries with the non-annealing interface. The batteries with the interface annealed at 450 °C show high Li3PO4–LiNi0.5Mn1.5O4 interface resistance of 490 Ω cm2, resulting in low battery performance. X-ray photoemission spectroscopy indicates that the P in Li3PO4 is reduced by high-temperature annealing, possibly causing the performance degradation of batteries. This study provides an in-depth understanding of the interfaces of solid-state batteries and is expected to facilitate the development of thermally stable batteries.

Heat Effects during the Operation of Lead-Acid Batteries

Thermal events in lead-acid batteries during their operation play an important role; they affect not only the reaction rate of ongoing electrochemical reactions, but also the rate of discharge and self-discharge, length of service life and, in critical cases, can even cause a fatal failure of the battery, known as “thermal runaway.” This contribution discusses the parameters affecting the thermal state of the lead-acid battery. It was found by calculations and measurements that there is a cooling component in the lead-acid battery system which is caused by the endothermic discharge reactions and electrolysis of water during charging, related to entropy change contribution. Thus, under certain circumstances, it is possible to lower the temperature of the lead-acid battery during its discharging. The Joule heat generated on the internal resistance of the cell due to current flow, the exothermic charging reaction, and above all, the gradual increase in polarization as the cell voltage increases during charging all contribute to the heating of the cell, overtaking the cooling effect. Of these three sources of thermal energy, Joule heating in polarization resistance contributes the most to the temperature rise in the lead-acid battery. Thus, the maximum voltage reached determines the slope of the temperature rise in the lead-acid battery cell, and by a suitably chosen limiting voltage, it is possible to limit the danger of the “thermal runaway” effect. The overall thermal conditions of the experimental cell are significantly affected by the ambient temperature of the external environment and the rate of heat transfer through the walls of the calorimeter. A series of experiments with direct temperature measurement of individual locations within a lead-acid battery uses a calorimeter made of expanded polystyrene to minimize external influences. A hitherto unpublished phenomenon is discussed whereby the temperature of the positive electrode was lower than that of the negative electrode throughout the discharge, while during charging, the order was reversed and the temperature of the positive electrode was higher than that of the negative electrode throughout the charge. The authors relate this phenomenon to the higher reaction entropy change of the active mass of the positive electrode than that of the negative electrode.

Long term performance evaluation of a commercial vanadium flow battery system

This paper describes the results of a performance review of a 10 kW/100 kWh commercial VFB system that has been commissioned and in operation for more than a decade. The evaluation focused on the system efficiencies, useable capacity, electrolyte stability and stack degradation. The analysis shows that the system has stable performance and very little capacity loss for over a decade since commissioning. Only very recently, a slight decrease in system discharge capacity (approximately 5 %) was observed and indicated by changes in the electrolyte valence state. The capacity was restored to the original level after conducting a rebalancing procedure. This demonstrates the advantage that the flow batteries employing vanadium chemistry have a very long cycle life. Furthermore, electrochemical impedance spectroscopy analysis was conducted on two of the battery stacks. Some degradation was observed in one of the stacks reflected by the increased charge transfer resistance. To further investigate the ageing of the stacks, reverse polarity tests were carried out. It is found that reversing the polarity both hydraulically and electrically can restore the stack performance. The study shows that the VFB is a reliable technology for large-scale energy storage applications.

Consummating ion desolvation in hard carbon anodes for reversible sodium storage

Hard carbons are emerging as the most viable anodes to support the commercialization of sodium-ion (Na-ion) batteries due to their competitive performance. However, the hard carbon anode suffers from low initial Coulombic efficiency (ICE), and the ambiguous Na-ion (Na+) storage mechanism and interfacial chemistry fail to give a reasonable interpretation. Here, we have identified the time-dependent ion pre-desolvation on the nanopore of hard carbons, which significantly affects the Na+ storage efficiency by altering the solvation structure of electrolytes. Consummating the pre-desolvation by extending the aging time, generates a highly aggregated electrolyte configuration inside the nanopore, resulting in negligible reductive decomposition of electrolytes. When applying the above insights, the hard carbon anodes achieve a high average ICE of 98.21% in the absence of any Na supplementation techniques. Therefore, the negative-to-positive capacity ratio can be reduced to 1.02 for full cells, which enables an improved energy density. The insight into hard carbons and related interphases may be extended to other battery systems and support the continued development of battery technology.

Two‐dimensional sp2‐carbon‐linked covalent organic framework for large‐capacity and long‐life Na metal batteries

AbstractNa metal batteries are regarded as an encouraging route for energy‐dense and low‐cost battery systems. However, the unstable and irreversible Na plating/stripping, caused by the uncontrolled dendritic Na growth, prevents their practical applications. Herein, a two‐dimensional sp2‐carbon‐linked covalent organic framework (cyano‐sp2c‐COF) is adopted as seeding/hosting coating layer for a highly stable interface with long cycling life, large capacity, and high Na utilization. Benefit from the features of a fully π‐conjugated structure and well‐defined cyano groups, cyano‐sp2c‐COF with superior sodiophilicity and small interface resistance can reduce the nucleation barrier, enable Na ion flux uniformity, and enhance interface stability. Ultimately, the system achieves a low nucleation overpotential of only 10 mV, a remarkable average Coulombic efficiency of 99.7% maintained over 500 cycles in half cells, and exceptional interfacial durability of 8500 h with a high accumulated capacity of 8.5 Ah cm−2 in symmetric cells. Furthermore, the symmetric cells also present a steady cycling, even increasing the depth of discharge up to 90%. As proof, full cells demonstrate a long lifespan enduring 2700 cycles with tiny capacity decay, providing valuable insights into the long‐life Na batteries.

Techno-economic feasibility of integrating hybrid-battery hydrogen energy storage in academic buildings

Green hydrogen production and storage are vital in mitigating carbon emissions and sustainable transition. However, the high investment cost and management requirements are the bottleneck of utilizing hybrid hydrogen-based systems in microgrids. Given the necessity of cost-effective and optimal design of these systems, the present study examines techno-economic feasibility of integrating hybrid hydrogen-based systems into an outdoor test facility. With this perspective, several solar-driven hybrid scenarios are introduced at two energy storage levels, namely the battery and hydrogen energy storage systems, including the high-pressure gaseous hydrogen and metal hydride storage tanks. Dynamic simulations are carried out to address subtle interactions in components of the hybrid system by establishing a TRNSYS model coupled to a Fortran code simulating the metal hydride storage system. The OpenStudio-EnergyPlus plugin is used to simulate the building load, validate against experimental data, according to the measured data and monitored operating conditions. Aimed at enabling efficient integration of energy storage systems, a techno-enviro-economic optimization algorithm is developed to simultaneously minimize the levelized cost of the electricity and maximize the CO2 mitigation in each proposed hybrid scenario. The results indicate that integrating the gaseous hydrogen and metal hydride storages into the photovoltaic-alone scenario enhances 22.6% and 14.4% of the annual renewable factor. Accordingly, the inclusion of battery system to these hybrid scenarios gives a 30.4% and 20.3 % boost to the renewable factor value, respectively. Although the inclusion of battery energy storage into the hybrid systems increases the renewable factor, the results imply that it reduces the hydrogen production rate via electrolysis. The optimized values of the levelized cost of electricity and CO2 emission for different scenarios vary in the range of 0.376–0.789 $/kWh and 6.57–9.75 ton, respectively. The multi-criteria optimizations improve the levelized cost of electricity and CO2 emission by up to 46.2% and 11.3%, with respect to their preliminary design.