Ah Capacity Research Articles

Molecular Design of Mono-Fluorinated Ether-Based Electrolyte for All-Climate Lithium-Ion Batteries and Lithium-Metal Batteries.

Fluorinated-ethers are promising electrolyte solvents in lithium metal batteries, for their high antioxidant and excellent reductive stability on Li anode. However, fluorinated-ethers with high fluorination degree suffer from low ionic conductivity and narrow temperature adaptibility. Herein, we synthesize a mono-fluorinated linear ether of bis(2-fluoroethoxy) methane (BFME) with enhanced solvated ability. The -OCH2O- structure and fluoride substitution on the β-C position endows the BFME electrolyte with moderate affinity to Li+, thereby improving the ionic conductivity and decreasing the Li+-desolvation energy barrier at a wide temperature range of -60-60 °C. Additionally, the electrolyte with anion-participated solvation structure demonstrates high film-forming ability by forming LiF-rich interfacial film on the electrode surfaces, rendering the graphite anode with an initial Coulombic efficiency (CE) of 94.9 % and a Li plating/stripping CE of 99.8 % by Aurbach method. Consequently, the Graphite||LiFePO4 pouch cells delivered 83.2 %, 92.5 % and 81.2 % capacity retention after 1250, 200 and 300 cycles at 25, -20 °C and 60 °C, respectively. Moreover, the Li||LFP pouch cell with 3 Ah capacity can operate for 65 cycles with 99 % capacity retention, verifying the effectiveness of the BFME electrolyte in stabilizing the interfaces and broadening the temperature adaptibility of lithium-ion and lithium metal batteries.

Scaling of Planar Sodium‐Nickel Chloride Battery Cells to 90 cm2 Active Area

High‐temperature sodium‐nickel chloride (Na‐NiCl2) batteries offer a competitive solution for stationary energy storage due to their long‐term stability, high energy efficiency, and sustainable raw materials. However, scaling up this technology faces challenges related to the costly integration of tubular Na‐β''‐alumina ceramic electrolytes into hermetically sealed battery cells. Alternative cell designs with a planar Na‐β''‐alumina ceramic electrolyte have been a focus of research for many years, and a series of achievements were made on cell design, on reduction of the operating temperature, and on the analysis of electrochemical reaction mechanisms. However, the data presented in these reports was derived from laboratory‐scale cells with small area (1‐5 cm2). To date, there has been no research conducted on enlarging planar cells to an economically viable size. Here we report the fabrication of large planar Na‐β''‐alumina electrolytes and their integration into planar Na‐NiCl2 cells with 90 cm2 active area and >7 Ah capacity. Our cell design enabled cycling at 300 °C for three months, transferring a cumulative capacity of 323 Ah. We discuss design and engineering considerations for large planar high‐temperature cells emphasizing the need for cell stacking to compete with tubular Na‐NiCl2 batteries in terms of mass‐specific energy.

Simplified Physics-Based Battery Model for Stationary Energy-Storage Applications

To perform safe battery operation and avoid unnecessary degradation, battery models are needed. How complex, or close to reality the model should be, depends on the purpose of the model and the computational power available. The possibility for accurate parameterization before model implementation is another crucial aspect for the validity. Physics-based models have the advantage to solve for internal battery states, which includes important information to avoid accelerated degradation and to evaluate state of health. But the parameterization effort can be extensive and the computational cost too high to solve for in real time. Identifying the most essential processes and if possible, simplify the model is therefore motivated.Parameter sensitivity is a powerful tool to investigate how much certain parameters and the related processes effect the output signal, i.e. battery voltage. Under normal operating conditions the cells are rarely completely discharged, and as a result the diffusion processes show low sensitivity during operation [1]. In this work we therefore explore the utilization of a physics-based model solving for the electrolyte dynamics, rather than the solid phase diffusion commonly applied in the so-called single particle model. By neglecting the diffusion processes, the second dimension in the pseudo-two-dimensional (P2D) model can be ignored and the computational complexity simplified. The parameterization strategy and validation of the model is further discussed.We evaluate our model by comparing simulations with experimental data from batteries subjected to stationary energy storage applications. The cells are commercial 18650-type NMC/Graphite cells with 2.6 Ah capacity. Different service cycles have different needs in terms of current and voltage, see examples in Figure 1. Capturing these behaviours with a physics-based model might pose different challenges and will further affect the degradation of the cells [2]. A wide range of models exist in literature to capture degradation mechanisms during battery operation [3]. To keep the computational and parameterization effort as low as possible, our methodology is not to include more physics, but instead update the parameters to the processes already included in the model [4]. We explore this strategy comparing the behaviour from different types of services, as well as batteries where the application changes, to see the model response and analyse the battery state of health, see Figure 2. Electrochemical techniques such as differential voltage analysis and electrochemical impedance spectroscopy is included to support our conclusions.Our results highlight the value of application considerations when designing battery models, rather than only focusing on physical extreme points. We present an alternative physics-based model with the ability to capture crucial degradation phenomena and validate it against operational data. We believe our findings can be of value for smarter battery operating strategies and a greater understanding of application dependant lithium-ion battery degradation.Figure 1. Some of the application duty cycles part of the experimental study. a) Current profile peak shaving b) Current profile frequency regulation c) Voltage response peak shaving d) Voltage response frequency regulation.Figure 2. Degradation trends from the experimental study. Purple cell initially performing PS following application change to FR_high cycling a) Capacity evolution of the cycled cells b) tortuosity parameter evolution obtained from model parameter fitting c) Measured impedance response during cell reference performance tests d) Calculated charge transfer resistance from measured impedance data.

Useful Quantities and Diagram Types for Diagnosis and Monitoring of Electrochemical Energy Converters Using Impedance Spectroscopy: State of the Art, Review and Outlook

The concept of pseudocapacitance is explored as a rapid and universal method for the state of health (SOH) determination of batteries and supercapacitors. In contrast to this, the state of the art considers the degradation of a series of full charge/discharge cycles. Lithium-ion batteries, sodium-ion batteries and supercapacitors of different cell chemistries are studied by impedance spectroscopy during lifetime testing. Faradaic and capacitive charge storage are distinguished by the relationship between the stored electric charge and capacitance. Batteries with a flat voltage–charge curve are best suited for impedance spectroscopy. There is a slight loss in the linear correlation between the pseudocapacitance and Ah capacity in regions of overcharge and deep discharge. The correct calculation of quantities related to complex impedance and differential capacitance is outlined, which may also be useful as an introductory text and tutorial for newcomers to the field. Novel diagram types are proposed for the purpose of the instant performance and failure diagnosis of batteries and supercapacitors.

Hybrid Ceramic Polymer Electrolytes Enabling Long Cycling in Practical 1 Ah‐Class High‐Voltage Solid‐State Batteries with Li Metal Anode

AbstractSolid polymer electrolytes offer a safer alternative to organic liquid electrolytes in high‐voltage lithium metal batteries, yet challenges remain in achieving adequate cyclability, energy density, scalability, and safety. This study presents the cycling performance of 1 Ah high‐voltage lithium polymer batteries featuring a hybrid ceramic polymer electrolyte (HCPE), a lithium metal anode, and a LiNi0.8Mn0.1Co0.1O2 (NMC‐811)‐based positive electrode. The HCPE stands out for its remarkable mechanical properties, with a Young's modulus exceeding 200 MPa at room temperature, providing robust resistance against dendrite formation. The Li||Li symmetric cells exhibited outstanding performance, cycling for over 1000 hours at a capacity of 2 mAh cm−2, highlighting the exceptional attributes of HCPE. Full cell testing is conducted under practical conditions, utilizing various cell configurations, from coin cells to large pouch cells with a 1 Ah capacity, achieving an energy density of nearly 250 Wh kg−1 and promising cyclability with 80% capacity retention after 110 cycles. The study also investigated thermal runaway characteristics, showing comparability with commercial lithium‐ion batteries. This research underscores the scalability and performance of high‐voltage lithium metal polymer batteries, advancing their potential for commercial viability.

Comparisons of different cooling systems for thermal management of lithium-ion battery packs: Phase change material, nano-enhanced channel cooling and hybrid method

Heat produced during the charging/discharging cycle must be dissipated for lithium-ion batteries to operate efficiently. Consequently, three distinct li-ion battery cooling systems were devised in this research, including phase-changing material (PCM), liquid-assisted, and hybrid, to allow lithium-ion batteries to run at the optimal operating temperature. To assess the efficiency of BTMS, the highest temperature and variation in temperature were examined. Without cooling system, simulations of the 20 Ah capacity battery pack were performed at various discharge rates (2C, 3C, and 4C). After that, an effective thermal management technique was identified by simulating PCM, liquid-assisted, and hybrid BTMS. The efficacy of PCM and BTMS was investigated at three different discharge rates. Water and Al2O3 nanofluid cooling medium thermal performance was investigated for liquid-supported BTMS at four distinct Reynolds numbers (Re) (250, 500, 750, and 1000), three distinct volume ratios (0.5 %, 1 %, and 2 %), and four distinct nanoparticle geometric shapes (Oblate spheroid, block, cylinder, and platelet). The influence of cooling channels on the thermal characteristics on PCM was investigated utilizing four various Re values and three distinct volume ratios, as well as the cooling effectiveness of hybrid BTMS. When the findings were analyzed, it emerged that hybrid BTMS improved the highest temperature by 28 %, while PCM and liquid-assisted cooling techniques enhanced peak temperature by 26 % and 27 %, correspondingly. However, when the temperature difference was analyzed, it was determined that only the hybrid and PCM reduced it to less than 5 °C, which is a suitable temperature difference. Paraffin can be cooled more efficiently by lowering the liquid stage distribution in the solid stage and the melting start time utilizing the hybrid cooling technique. Because of this, it has been determined that hybrid BTMS is the optimal cooling approach for the battery module.

RANCANG BANGUN PROTOTIPE SISTEM BATTERY CHARGER DENGAN METODE PENGISIAN TIGA TAHAP DI PERUMDA AIR MINUM TIRTA SANJIWANI UNIT PRODUKSI BLANGSINGA

Generator set (genset) is needed in companies that operate continuously such as at Perumda Air Minum Tirta Sanjiwani to supply electrical equipment when there is a disruption in the main supply, therefore, the generator set must always be ready to use, one way is through charging the battery with the right method to maintain battery capacity to always be in full condition. This research discusses related to the Battery Charger System Prototype which integrates microcontroller components, sensors, actuators, indicators, and converters to be able to charge the battery with a three-stage charging method and be able to perform a preventive response when a voltage outside the charging standard is detected to minimize the risk of battery damage. Test results using a 10 Ah capacity battery when the DOD is 50% show that charging through the Bulk Stage lasts for 6 hours 40 minutes with a charging current set at 0.7 A, the Absorption Stage lasts for 1 hour 17 minutes with a charging voltage set at 14.7 V, and the Float Stage is tested for 2 hours with a charging voltage set at 13.65 V. This research also includes two battery charging current options to be implemented to partners, so it is expected to provide adequate solutions.

Pentafluoro(phenoxy)cyclotriphosphazene Stabilizes Electrode/Electrolyte Interfaces for Sodium-Ion Pouch Cells of 145 Wh Kg-1.

Sodium-ion batteries are competitive candidates for large-scale energy storage batteries due to the abundant sodium resource. However, the electrode interface in the conventional electrolyte is unstable, deteriorating the cycle life of the cells. Introducing functional electrolyte additives can generate stable electrode interfaces. Here, pentafluoro(phenoxy)cyclotriphosphazene (FPPN) serves as a functional electrolyte additive to stabilize the interfaces of the layered oxide cathode and the hard carbon anode. The fluorine substituting groups and the π-π conjugated ─PN─ structure decrease the lowest unoccupied molecular orbital and increase the highest occupied molecular orbital of FPPN, respectively, realizing the preferential reduction and oxidization of FPPN on the anode and cathode simultaneously, which results in the formation of a uniform, ultrathin, and inorganic-rich solid electrolyte interlayer and cathode electrolyte interphase. The sodium-ion pouch cells of 5 Ah capacity rather than coin cells are assembled to evaluate the effect of FPPN. It can retain a high capacity of 4.46 Ah after 1000 cycles, corresponding to a low decay ratio of 0.01% per cycle. The pouch cell also achieves a high energy density of 145Wh kg-1 and a wide operating temperature of -20-60°C. This work can attract more attention to the rational electrolyte design for practical applications.

Optimized ANN for LiFePO4 battery charge estimation using principal components based feature generation

Electric vehicles (EVs) have gained prominence in the present energy transition scenario. Widespread adoption of EVs necessitates an accurate State of Charge estimation (SoC) algorithm. Integrating predictive SoC estimations with smart charging strategies not only optimizes charging efficiency and grid reliability but also extends battery lifespan while continuously enhancing the accuracy of SoC predictions, marking a crucial milestone in sustainable electric vehicle technology. In this research study, machine learning methods, particularly Artificial Neural Networks (ANN), are employed for SoC estimation of LiFePO4 batteries, resulting in efficient and accurate estimation algorithms. The investigation first focuses on developing a custom-designed battery pack with 12 ​V, 4 Ah capacity with a facility for real-time data collection through a dedicated hardware setup. The voltage, current and open-circuit voltage of the battery are monitored with computerized battery analyzer. The battery temperature is sensed with a DHT22 temperature sensor interfaced with Raspberry Pi. Principal components are derived for the collected battery data set and analyzed for feature engineering. Three principal components were generated as input parameters for the developed ANN. Early Stopping for the ANN was also implemented to achieve faster convergence of the ANN. While considering eleven combinations for ten different optimizers loss function is minimized. Comparative analysis of hyperparameter tuning and optimizer selection revealed that the Adafactor optimizer with specific settings produced the best results with an RMSE value of 0.4083 and an R2 Score of 0.9998. The proposed algorithm was also implemented for two different types of datasets, a UDDS drive cycle and a standard cell-level dataset. The results obtained were in line with the results obtained with the ANN model developed based on the data collected from the developed experimental setup.

Cathode Active Material Synthesis and Battery Performance Tests for Li-Ion Batteries Obtained from Domestic Raw Materials: A Special Case Study from Ore to Battery

The energy requirement brought by technological developments from the past to the present evolves depending on the society's desire to be mobile, which is increasing day by day. Many technological devices such as electrical vehicles, smart phones, computers, drones, cameras meet the required energy from rechargeable lithium-ion batteries. However, the increasing world population and the increasing specifications of the technological devices developed in parallel with the per capita energy consumption by making the raw material resources needed for the production of these technological devices even more important. Nickel, cobalt and manganese compounds, which are the main raw materials used in the cathode production of NMC type lithium-ion batteries, are among these elements of strategic and critical importance, and the production of these chemicals in appropriate quality is of great importance for the industrial development of lithium-ion-based domestic battery technologies in each country. Meta Nikel Kobalt A.Ş., is the first and the only industrially scaled nickel-cobalt plant using HPAL technology in northern hemisphere at . In Gördes plant, nickel-cobalt-manganese hydroxide intermediate product concentrate (MHP) is produced from low grade Gördes lateritic ore following the unit operations of ore preparation, mineral processing, high pressure acid leaching, neutralization and precipitation and is currently completely exported to overseas. However, due to the responsibility of transforming domestic resources to high value-added technological products and obtaining value-added products, research in this field has been regarded and the necessary technological infrastructure and specific knowledge have been created. Within the scope of this project, precious metals in the MHP intermediate product obtained from Gördes lateritic ore were leached and valuable elements are taken to the liquid phase and crystallized after further purification processes such as solvent extraction and ion exchange. As a result, metal salts with purity up to 99.99% were obtained. The obtained nickel, cobalt and manganese sulphate salts were precipitated together with the developed co-precipitation process to obtain precursor in the form of NMC 622. After that, the precursor is treated with lithium and the cathode active material (CAM) is obtained by going through various heat treatments by systematically designed test campaign. The coin cell made with the CAM obtained from domestic raw materials showed a capacity of 184.55 mAh/g at 0.1C. It showed a capacity of 170.58 mAh/g in the first cycle and 157.45 mAh/g in the 50th cycle at 0.5 C, and the capacity conservation was calculated as 92.3% after 50 cycles at 0.5 C. The CAM obtained in the pilot-scale studies carried out according to the lab-scale developed process and sent to for making pouch type battery. In the 10 Ah capacity cells of the produced pouch type, 82% capacity conversation has been achieved as a result of 1000 cycles at a charge/discharge rate of 0.5 C at 100% CoC(Dept of Discharge) in the voltage range of 3-4.15V. Figure 1

Aqueous Processing of Ni-Rich NMC Electrodes with High Areal Capacity and Excellent Long-Term Cycling Stability

Research efforts in the last three decades have resulted in a steady increase in the energy density of Li-ion batteries (LIBs), leading to their integration into electric vehicles (EVs). Therefore, car manufacturers have increased the number of EVs in their fleets and successfully introduced them to the mass market, with 200M of EVs expected to be sold by 2025 [1] . In such a fast-growing market, the cost and environmental impact of LIB production play major roles. A crucial step in battery manufacturing is the processing of active materials to produce electrode coatings. Commercial cathode electrodes (i.e. LiNixMnxCoxO2 (NMC), LiNi0.5Mn1.5O4 (LNMO) etc.) are still largely processed using organic solvents, specifically N-methyl-2-pyrrolidone (NMP), with poly(vinylidene difluoride) (PVDF) as a binder. However, the NMP-PVDF combination has many disadvantages [2]. Firstly, the binder is considerably more expensive than water-soluble binders and not easy to dispose of at the end of the battery life. Secondly, NMP is costly and toxic, and being a volatile organic compound (VOC), needs solvent recovery at commercial scale. On the other hand, water-soluble binders such as Na-carboxymethylcellulose (Na-CMC) and styrene butadiene rubber (SBR) are not only cheaper but also easier-to-recycle [3]. Additionally, the use of water as a solvent would remove the need for solvent recovery. It is then clear that switching to water-based processing for cathode materials would decrease cost and improve the environmental sustainability of LIB production. Nevertheless, aqueous cathode processing has many challenges [2], the major one being the instability of the active material in water. The leaching of Li+ ions gives rise to very high pH (~ 12) values which, in turn, leads to the corrosion of the current collector (aluminium) and gas evolution during coating. Consequently, electrodes usually show cracks and pinhole defects and exhibit poor flexibility. These issues are even more enhanced for thick coatings, which are needed to achieve high energy density cells. Therefore, the electrochemical performance of water-based cathode electrodes is generally poorer than that for NMP-based electrodes.In this work, the effect of additions of phosphoric acid (H3PO4) on slurry rheology, adhesion strength, electrode morphology and the electrochemical performance of Ni-rich NMC cathodes prepared via water-based processing was investigated. To effectively bridge the gap between lab-scale investigations and industrially applicable procedures, pH control of the slurries and roll-to-roll electrode coating were performed at the pilot scale, and only electrodes exhibiting commercially relevant areal capacities (~ 4-4.5 mAh cm-2), high active material contents (> 90%) and low binder amounts (3 wt.%) were investigated. Phosphoric acid was added in amounts between 1.5 and 3 wt.%, and a fast-mixing procedure was developed to minimize the contact time between the NMC particles and water. The pH evolution over time showed that at least 2 wt.% of H3PO4 is required to keep the pH below the corrosion threshold of aluminium (pH < 9) for 6-8 hours, which is a usual time scale for industrial electrode processing. All slurries showed shear thinning behaviour with the viscosity of the water-based slurries being slightly lower than that for NMP-based slurries at the shear rate used for coating. Optical micrographs of coated electrodes showed no evidence of defects or agglomerates and good homogeneity. The adhesion to the current collector decreased with increasing amount of acid, e.g., electrodes prepared using 3 wt.% H3PO4 showed cracks at the edges of the coating and delamination.The long-term performance and rate capability of the electrodes were investigated in full-cell configuration vs graphite (coin-cell setup). NMC cathodes prepared with 1.5 wt.% acid showed a specific capacity of around 180 mAh g-1 at C/10 and 165 mAh g-1 at C/3. The specific capacity of the cells decreased with increasing amount of acid. The water-based and NMP electrodes retained around 50% and 60% of the initial capacity at 1C, respectively. Furthermore, electrodes prepared with 1.5 wt.% and 2.25 wt.% acid achieved a capacity retention above 90% after 500 cycles, which is comparable to NMP-based electrodes. In a further step, the production of the electrodes was upscaled in order to manufacture NMC/graphite pouch cells of 10 Ah capacity. These cells showed excellent cycling stability, reaching 80% SoH after 1500 cycles.

The Impact of a Combined Battery Thermal Management and Safety System Utilizing Polymer Mini-Channel Cold Plates on the Thermal Runaway and Its Propagation

Lithium-ion batteries are widely used in mobile applications because they offer a suitable package of characteristics in terms of specific energy, cost, and life span. Nevertheless, they have the potential to experience thermal runaway (TR), the prevention and containment of which require safety measures and intensive thermal management. This study introduces a novel combined thermal management and safety application designed for large aspect-ratio battery cells such as pouches and thin prismatics. It comprises polymer-based mini-channel cold plates that can indirectly thermally condition the batteries’ faces with liquid. They are lightweight and space-saving, making them suitable for mobile systems. Furthermore, this study experimentally clarifies to which extent the application of polymer mini-channel cold plates between battery cells is suitable to delay TR by heat dissipation and to prevent thermal runaway propagation (TRP) to adjacent cells by simultaneously acting as a thermal barrier. NMC pouch cells of 12.5 Ah capacity were overcharged at 1 C to induce TR. Without cold plates, TR and TRP occurred within one hour. Utilizing the polymer mini-channel cold plates for face cooling, the overcharge did not produce a condition leading to cell fire in the same time frame. When the fluid inlet temperature was varied between 5 and 40 °C, the overcharged cell’s surface temperature peaked between 50 and 60 °C. Indications were found that thermal conditioning with the polymer cold plates significantly slowed down parts of the process chain before cell firing. Their peak performance was measured to be just under 2.2 kW/m2. In addition, thermal management system malfunction was tested, and evidence was found that the polymer cold plates prevented TRP to adjacent cells. In conclusion, a combined thermal management and safety system made of polymer mini-channel cold plates provides necessary TR-related safety aspects in lithium battery systems and should be further investigated.

Experimental Investigation on Affecting Air Flow against the Maximum Temperature Difference of a Lithium-Ion Battery with Heat Pipe Cooling

Research on battery thermal management systems (BTMSs) is particularly significant since the electric vehicle sector is growing in importance and because the batteries that power them have high operating temperature requirements. Among them, heat pipe (HP)-based battery thermal management systems have very high heat transfer performance but fall short in maintaining uniform temperature distribution. This study presented forced air cooling by an axial fan as a method of improving the cooling performance of flat heat pipes coupled with aluminum fins (FHPAFs) and investigated the impact of air velocity on the battery pack’s maximum temperature differential (ΔTmax). All experiments were conducted on lithium nickel manganese cobalt oxide (NMC) pouch battery cells with a 20 Ah capacity in seven series connections at room temperature, under forced and natural convection, at various air velocity values (12.7 m/s, 9.5 m/s, and 6.3 m/s), and with 1C, 2C, 3C, and 4C discharge rates. The results indicated that at the same air velocity, increasing the discharge rate increases the ΔTmax significantly. Forced convection has a higher ΔTmax than natural convection. The ΔTmax was reduced when the air velocity was increased during forced convection.

Cell design strategies for sodium-zinc chloride (Na-ZnCl2) batteries, and first demonstration of tubular cells with 38 Ah capacity

Cell design strategies for sodium-zinc chloride (Na-ZnCl2) batteries, and first demonstration of tubular cells with 38 Ah capacity

Pembangkit Listrik Tenaga Air (PLTA) Portable Berbasis IoT

Based on the increasing need for electricity for the community, especially in the Bangka Belitung region, which still uses a lot of expensive fossil energy (generators), so it is still a cost constraint for people living in remote areas that have not been electrified. So it is necessary to innovate in making electricity that utilises natural resources (water). However, the problem is that water sources in some places have erratic water discharge. Therefore, in this research it is proposed to make a portable hydropower plant so that it can be moved in a place that has a high water discharge that can monitor the rpm, voltage and current of the generator and battery and is expected to be used as a cheap and environmentally friendly alternative power plant. The methodology in making this hydropower plant uses a 100Watt DC generator with a 12-bladed breadshot turbine type and is controlled using LM393 sensors and INA219 sensors with a monitoring system using the Blynk application by utilising IoT-based technology. The test was conducted by testing the effect of generator rpm speed on generator current and voltage, battery charging and discharging time, and testing the monitoring system using the Blynk application. From the test results, it is obtained that the minimum generator rpm that must be achieved when charging the battery is 425 rpm with the power obtained of 12.19Watt. Charging a 50 Ah capacity battery at the hydropower plant takes 6 hour and 38 minutes with a charging current of 6,7A. While for battery discharge using a 12V 75Watt lamp load takes 7 hours 25 minutes. The generator monitoring system using the Blynk application works well in displaying the same measurement results on the LCD screen with an accuracy value of 100%.

Combined Utilization of Cylinder and Different Shaped Alumina Nanoparticles in the Base Fluid for the Effective Cooling System Design of Lithium-Ion Battery Packs

It is important to consider the thermal management of lithium-ion batteries to overcome their limitations in usage and improve their performance and life cycles. In this study, a novel cooling system for the thermal management of lithium-ion battery packs is proposed by using an inner cylinder in the cooling channel and different-shaped nanoparticles in the base fluid, which is used as the cooling medium. The performance improvements in a 20 Ah capacity battery are compared by using a water–boehmite alumina (AlOOH) nanofluid, considering cylinder-, brick-, and blade-shaped nanoparticles up to a solid volume fraction of 2%. The numerical analysis is conducted using the finite element method, and Reynolds numbers between 100 and 600 are considered. When the efficacy of the coolants utilized is compared, it is apparent that as the Reynolds number increases, both cooling media decrease the highest temperature and homogenize the temperatures in the battery. The utilization of the cylinder in the mini-channel results in a 2 °C temperature drop at Re = 600 as compared to the flat channel. A boehmite alumina nanofluid with a 2% volume fraction reduces the maximum temperature by 5.1% at Re = 200. When the shape effect of the nanofluid is examined, it is noted that the cylinder-shaped particle improves the temperature by 4.93% as compared to blade-shaped nanoparticles and 7.32% as compared to brick-shaped nanoparticles. Thus, the combined utilization of a nanofluid containing cylindrical-shaped nanoparticles as the cooling medium and a cylinder in the mini-channel of a battery thermal management system provides an effective cooling system for the thermal management of the battery pack. The outcomes of this work are helpful for further system design and optimization studies related to battery thermal management.

Fluorine-free water-based Ni-rich positive electrodes and their performance in pouch- and 21700-type cells

In recent years substantial progress has been made in the lab-scale aqueous processing of cathode electrodes containing Ni-rich active materials such as LiNi0.83Co0.12Mn0.05O2. Now it has to be proven in production-scale that such an environmentally-friendly, water-based process will deliver cells with competitive performance. We demonstrate the upscaling of a carboxymethyl cellulose and styrene-butadiene rubber based electrode-coating recipe from 250 mL lab-scale to 10 L production-scale by coating a double-sided electrode with 140 m length, very homogeneous mass loading, and excellent roll to roll processability. Several challenges such as the control and stabilization of slurry pH and fine adjustment of the mixing and coating time have been solved. The organic- and H2O-based pilot scale cathode electrodes with areal capacities of 3.0 mAh cm−2 were characterized in pouch- and 21700-type cylindrical cells. The cells were cycled at room temperature and 45 °C for up to 2000 cycles at 1C/1C. Pouch cells containing H2O-based electrodes show a high capacity retention of 79.3% after 1000 cycles. Similarly, H2O-based electrodes built into 21700-type cells with 3.5 Ah capacity achieved 80% after 1000 cycles at 1C/1C cycling.

Performance Leap of Lithium Metal Batteries in LiPF6 Carbonate Electrolyte by a Phosphorus Pentoxide Acid Scavenger.

Phosphorus pentoxide (P2O5) is investigated as an acid scavenger to remove the acidic impurities in a commercial lithium hexafluorophosphate (LiPF6) carbonate electrolyte to improve the electrochemical properties of Li metal batteries. Nuclear magnetic resonance (NMR) measurements reveal the detailed reaction mechanisms of P2O5 with the LiPF6 electrolyte and its impurities, which removes hydrogen fluoride (HF) and difluorophosphoric acid (HPO2F2) and produces phosphorus oxyfluoride (POF3), OF2P-O-PF5- anions, and ethyl difluorophosphate (C2H5OPOF2) as new electrolyte species. The P2O5-modified LiPF6 electrolyte is chemically compatible with a Li metal anode and LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode, generating a POxFy-rich solid electrolyte interphase (SEI) that leads to highly reversible Li electrodeposition, while eliminating transition metal dissolution and cathode particle cracking. The excellent electrochemical properties of the P2O5-modified LiPF6 electrolytes are demonstrated on Li||NMC622 pouch cells with 0.4 Ah capacity, 50 μm Li anode, 3 mAh cm-2 NMC622 cathode, and 3 g Ah-1 electrolyte/capacity ratio. The pouch cells can be galvanostatically cycled at C/3 for 230 cycles with 87.7% retention.

Integrated Fuzzy-Logic and Triple-Loop PI-Based Management Strategy for a Lead-Acid/Lithium-Ion Hybrid Battery Energy Storage System

The huge success of electric vehicles across the world is challenged by a lack of infrastructure and a major increase in battery material prices. This challenge positions internal combustion engine vehicles (ICEVs) to remain a vehicle of choice. The majority of these vehicles use a lead-acid battery (LAB) for starting, lighting, and ignition (SLI) functions. However, these LABs are faced with challenges of short lifespan and low storage capacity because of improved electronic systems in modern ICEVs. In this manuscript, we propose an extension application of a hybrid LAB and lithium-ion energy storage system (ESS) for a vehicle using a single source of 70 Ah and 90 Ah capacity. Whereas previously, a hybrid energy storage system (HESS) for use in a vehicle using a source of 50 Ah battery capacity was proposed. Hence, the unique contribution of the study is using an integrated fuzzy-logic and triple-loop-proportional-integral-based battery management strategy (BMS) to improve LAB performance in a wide range of vehicles with different battery capacities sizes. The results show that the proposed BMS can help increase LAB lifespan and improve the storage capacity of the system, thus ensuring reliability. Additionally, compared to a single use of LAB, the combined energy storage system shows superior performance.

Prevention, Mitigation and Correlative Acoustic Spectroscopy of Lithium-Ion Battery Thermal Runaway

Scrutiny of lithium-ion battery failure has seen heavy regulations and restrictions with well-reported headlines of catastrophic thermal runaway of commercial electronic devices and electric vehicles. Thermal runaway occurs at a critical temperature when the rate of heat generation exceeds that of dissipation, highly exothermic decomposition reactions occur and temperatures in excess of 600 ᵒC can be measured 1. These concerns continue to grow with applications of greater energy density and capacity, such as the proliferation of electric vehicles.Isolation of electronically conductive components within the electrode assembly to prevent short circuit has shown promise to prevent the onset of thermal runaway within lithium-ion cells. Here 2, the authors present a metal-coated polymer current collector (PCC) and thermally stable separator (TSS) to prevent and mitigate thermal runaway. 2.10 Ah capacity 18650-geometry cells were subject to thermal, internal short circuit and nail penetration abuse techniques with these materials and their commercial counterparts for individual comparison of the PCCs and TSS. Reductions in cell mass were observed on the order of 5%, due to the majority of the PCC consisting of the polymer substrate rather than pure aluminium and copper in commercial current collectors. High speed synchrotron facilities provided insights into the function of the polymer current collectors with post- mortem X-ray computed tomography. During mitigation testing, cells were taken to failure with thermal and with an internal short circuit device (ISCD) within a Fraction Thermal Runaway Calorimeter (FTRC) to measure the reduction in calorific output. This highlighted the difficulty that exists with detecting gas-induced and internal structural degradation within lithium-ion batteries, especially outside specialized diagnostic laboratories to characterize these rapid changes with elapse within seconds. Attenuation and wave velocity determined by the propagative properties of ultrasound through different phases, prominently highlights structural, temperature and formation of different phases which occur during thermal runaway. Such analysis provided by acoustic spectroscopy are characterised by variations in the attenuation and signal peak shifts. Further information which can be derived from spatial mapping using acoustic spectroscopy 3,4 include: state of charge, state of health, electrochemical performance.Cells made with the aluminium-coated PCC demonstrated 100% success in prevention of thermal runaway during nail penetration, retaining a voltage above 4.00 V. Cells manufactured with the PCC, both PCC and TSS, exhibited a reduction in total energy output on average of 19.4% and 41.3% respectively during thermal abuse. ISCD triggered thermal runaways also observed reductions of 24.6% and 30.3% with these respective cell material configurations. Prevention of thermal runaway is a transformative advancement in improving lithium-ion battery safety, especially in the cylindrical 18650-format cell. Additionally, significant reductions in the calorific output during failure were measured. These safety innovations provides efficacy of these materials independent of cell chemistry (provided they are stable in the operating environment) while also increasing the energy density and be assimilated into existing manufacturing technology.Furthermore, the authors demonstrate correlative high-speed acoustic spectroscopy during routine cycling of a commercial 210 mAh lithium-ion pouch cell and during thermal abuse 5. Mechanical deformation such as gas-induced delaminations, which have been linked to degradation in electrochemical performance, capacity retention, cell state of health and impending thermal runaway, were detected. This degradation was observed with characteristic acoustic spectroscopy signal peaks changes during cycling due to cell manufacturing defects and during induced thermal abuse, were corroborated with high speed synchrotron X-ray imaging. This analysis can be observed immediately after application of the acoustic probe which emphasises the rapid diagnostics insights provided by acoustic spectroscopy as a robust field deployable technique. Thus, integration into battery management systems, second-life evaluation/recycling or as in-line cell metrology during manufacturing would provide real time direct insight into these metrics. Finegan DP, Darcy E, Keyser M, et al. Identifying the Cause of Rupture of Li-Ion Batteries during Thermal Runaway. Adv Sci. 2018. doi:10.1002/advs.201700369Pham MTM, Darst JJ, Walker WQ, et al. Prevention of lithium-ion battery thermal runaway using polymer-substrate current collectors. Cell Reports Phys Sci. 2021. doi:10.1016/j.xcrp.2021.100360Robinson JB, Pham M, Kok MDR, Heenan TMM, Brett DJL, Shearing PR. Examining the Cycling Behaviour of Li-Ion Batteries Using Ultrasonic Time-of-Flight Measurements. J Power Sources. 2019;444.Robinson JB, Maier M, Compton T, Alster G, Brett DJL, Shearing PR. Spatially resolved ultrasound diagnostics of Li-ion battery electrodes. Phys Chem Chem Phys. 2018. doi:10.1039/c8cp07098aPham MTM, Darst JJ, Finegan DP, et al. Correlative acoustic time-of-flight spectroscopy and X-ray imaging to investigate gas-induced delamination in lithium-ion pouch cells during thermal runaway. J Power Sources. 2020;470:228039. doi:10.1016/j.jpowsour.2020.228039