Battery Cycle Life Research Articles

Unit vector template control strategy‐based harmonic mitigation and charging with three phase–three level–three switch Vienna rectifier for Level 3 electric vehicle charging applications

SummaryFast battery charging units act as non‐linear loads, which induce a more harmonic effect in the utility grid. Hence, maintaining the stable voltage, current ripple, and total harmonic distortions within the permissible IEEE std level during the charging time of grid to electric vehicle (G2V) has become an important task for researchers in the future. In order to mitigate power fluctuations during every charging cycle, it will enhance the battery life cycle in electric vehicles (EVs). Three phase–three level–three switch Vienna rectifier with fuzzy logic controller tuned PID controller is used here for AC/DC conversion with minimum switching loss. A fuzzy intelligent control strategy has been employed with the DC link voltage regulator in order to sustain the DC link voltage as constant and progress the voltage/current profile by injecting active power at the point of common coupling. Unit vector template (UVT)‐based control strategy is employed here to identify the fundamental components from the load side and also estimate the reference phase current. This scheme enhances the performance and reduces the mathematical system complexity to diminish the harmonics in the distribution grid. The adaptability and feasibility of this proposed control method have been verified by the MATLAB simulation tool. To validate the response of the Vienna Rectifier with UVT controller are simulated with different unbalanced load conditions and also verified with 30 kW laboratory prototype experimental results using dsPIC30F4011 controller and the switch is IRFP260 with power diode RHRG30120.

Amorphization of Inorganic Solid Electrolyte Interphase Components and Its Impact on Enhancing Their Transport and Mechanical Properties.

The safety and cycle life of lithium-ion batteries (LIBs) are largely determined by the solid electrolyte interphase (SEI) formed on the surface of the anode. However, there is still a lack of understanding regarding the structure and properties of the individual SEI components. Among others, lithium oxide (Li2O), lithium carbonate (Li2CO3), and lithium fluoride (LiF) are known to be the main components of the inorganic SEI layer in conventional LIBs, but their intrinsic protective roles remain controversial. Herein, we present the transformational effects of their amorphous phase on the mechanical and transport characteristics, based on first-principles calculations. Our studies clearly demonstrate that their amorphous phases exhibit significantly improved Li-ion conductivity when compared to the crystalline structures. Additionally, among them, amorphous LiF emerges as a frontrunner for fast Li+ ion transportation, reversing the conventionally understood hierarchy. Under ambient conditions, the amorphous phases of LiF, Li2O, and Li2CO3 are thermodynamically unstable and tend to undergo recrystallization. However, this work highlights that exceptionally ductile and resilient amorphous phases can form if SEI formation and growth would involve some admixing of lithiophilic impurities like nitrogen (N) within the host matrices.

Direct regeneration of spent lithium-ion batteries: A mini-review

Recycling spent lithium-ion batteries (LIB) has emerged as a pressing necessity for addressing resource shortages and mitigating environmental pollution. This article reviews the most advanced spent LIBs recycling technology, namely direct regeneration. Traditional recycling methods have problems with high energy consumption and secondary pollution. In contrast, direct regeneration extends battery life by repairing degraded cathode materials and retains battery energy to the maximum extent. This method includes technologies such as chemical lithiation and recycling of waste graphite. These innovative technologies improve battery cycle life, reduce energy consumption, production costs, and promote sustainable resource management. Direct regeneration technology provides new opportunities to reduce resource waste and reduce environmental pollution. It will promote the sustainable management of spent LIBs and support the development of future renewable energy technologies.

Niobium Oxide Anode with Lattice Structure Self-Optimization for High-Power and Nearly Zero-Degeneration Battery Operation.

Li+ insertion-induced structure transformation in crystalline electrodes vitally influence the energy density and cycle life of secondary lithium-ion battery. However, the influence mechanism of structure transformation-induced Li+ migration on the electrochemical performance of micro-crystal materials is still unclear and the strategy to profit from such structure transformation remains exploited. Here, an interesting self-optimization of structure evolution during electrochemical cycling in Nb2O5 micro-crystal with rich domain boundaries is demonstrated, which greatly improves the charge transfer property and mechanical strength. The lattice rearrangement activates the Li+ diffusion kinetics and hinders the particle crack, thus enabling a nearly zero-degeneration operation after 8000 cycles. Full cell paired with lithium cobalt oxides displays an exceptionally high capacity of 176mAhg-1 at 8000mAg-1 and excellent long-term durability at 6000mAg-1 with 63% capacity retention over 2000 cycles. Interestingly, a unique fingerprint based on the intensity ratio of two X-ray diffraction peaks is successfully extracted as a measure of Nb2O5 electrochemical performance. The structure self-optimization for fast charge transfer and high mechanical strength exemplifies a new battery electrode design concept and opens up a vast space of strategy to develop high-performance lithium-ion batteries with high energy density and ultra-long cycle life.

Electrolyte-concentration dependent formation of artificial interface for prolonging the cycle life of Li-based anion storage batteries

The cycle life of anion-storing carbon cathodes suffers from parasitic side reactions on the electrode surface during high-voltage cycling. As a precautionary measure, the surface is protected by the artificial interface formed via electrochemical techniques using different concentrations of electrolytes. The chemical nature of the interfaces varies depending on the concentration of electrolyte, so the electrochemical performances. The interface formed in 0.3 M electrolyte is driven by the electrolyte solvent, rich in organic components (carbonates and phosphates), and undergoes dynamic changes during cycling, thereby yielding poor electrochemical performance. The percentages of inorganic components increase slightly in 1 M electrolyte and the cycling efficiencies improve to some extent. In contrast, the interface of 3 M electrolyte is dominated by the electrolyte salt (LiPF6)-derived inorganic products (LixPOy, POxFy, and CFx) and endows high-voltage protection to the greatest extent. The mechanochemically robust layer enhances interfacial stability, reduces side reactions, minimizes the growth of resistance, and safeguards the bulk of the material from premature failure. The modified electrode in 3 M electrolyte retains 85 % capacity after 500 cycles, while the unmodified electrode fails drastically within 50 cycles. The approach is equally applicable to LiNi0.5Mn1.5O4 cathode that stores Li+ at high voltage.

Advances in boron nitride‐based materials for electrochemical energy storage and conversion

AbstractEnergy storage and conversion (ESC) devices are regarded as predominant technologies to reach zero emission of carbon dioxide, which still face many challenges, such as poor safety, limited cycle life, low efficiency, etc. Hexagonal boron nitride (h‐BN), distinguished by its robust mechanical strength, chemical inertness, exceptional thermal stability, and superior ion conductivity, has appeared to meet some challenges of ESC devices. Typically, h‐BN can act as a perfect modifier to enhance the safety of batteries by improving the mechanical strength and heat dissipation of separators, extend cycle life of Li metal batteries by protecting solid state electrolyte from reducing and increase efficiency of fuel cells by improving the proton conductivity of membranes. Besides, recent progress on doping, surface modification, tailoring quantum dots, heterostructures, and hybridizations with other nanomaterials has made it possible to extensively apply h‐BN to other ESC technologies. This review provides a comprehensive overview of the up‐to‐date synthetic strategies for BN‐based materials and discusses the most recent breakthroughs on their application in electrochemical ESC technologies. Also, the challenges and future development for BN‐based materials in these fields are assessed.

Experimental Investigation of a Lead-Acid Battery Regeneration Technique for Improved Energy Efficiency

Currently, extensive advancements have been made in battery technology. After years of study and development, researchers have been examining batteries with a primary focus on finding ways to enhance their efficiency, dependability, and lifespan. This research aims to effectively extend the lifespan of lead-acid batteries by using appropriate methodology. The investigations demonstrate that injecting electric pulses during the charging process improves battery capacity and cycle life. The enhanced efficiency is a result of the elimination of lead sulphate buildup on the battery’s electrodes. These tests ensure successful regeneration of the battery’s capacity and optimise the regeneration process. Using electric pulses during the charging process can help minimise the formation of lead sulphate on the electrodes. The proposed technique covers five cycles of charge and discharge, leading to improved battery performance with a 23% increase in the state of charge (SoC) at the end of the charge mode. Furthermore, the suggested method enhances battery performance by elevating the recovered charge capacity from 60% to an impressive 90%. Extensive tests and experiments have confirmed the accuracy of these findings. Consequently, the improved lead-acid battery has a remarkable efficiency improvement of approximately 34%, making it useful and highly practical.

3D hierarchically fractal structure stabilized anode for achieving long-term cycle life of aqueous Zn-ion batteries

The cycling stability of aqueous Zn-ion battery (AZIB) is a serious issue for their successful application, mainly due to the considerable growth of Zn dendrites and the existence of side effects during operation. Herein, the hierarchically three-dimensional (3D) fractal structure of the ZnO/Zn/CuxO@Cu (ZZCC) anode is prepared by a two-step process, where CuxO nanowires are prepared on Cu foam by thermal oxidation method and Zn layer and ZnO surface are formed by plating. This fractal structure increases the electrodynamic surfaces and reduces the local current density, which can regulate Zn plating and inhibit dendritic growth and side effects. Apparently, the symmetric ZZCC-based cell shows a long-term operation time of 3000 h at 1 mA cm−2 with 1 mAh cm−2, and an operation time of more than 1000 h with a discharge depth of 15.94%. Compared with the bare Zn foil anode, the AZIB assembled with the composite of Mn-doped vanadium oxide and reduced graphene oxide cathode and ZZCC anode (MnVO@rGO//ZZCC) exhibits significantly improved cyclability (i.e. with 88.5% capacity retention) and achieves a Coulomb efficiency of 99.4% at 2 A g-1. This hierarchically 3D structure strategy to design anodes with superior cyclic stability contributes to the next generation of secure energy.

Can We See SEI Directly byNaked Eyes?

Stable solid electrolyte interface (SEI) is the key to improve the electrochemical performance of lithium metal batteries (LMBs). However, there are still many puzzles about SEI film that have not been well explained, due to the complexity of electrochemical reactions involving in SEI formation and the absence of direct observation methods for SEI. Here, this work realizes the direct observation of SEI by skillfully designed fluorescent tracers acting as an SEI film-forming additive for electrolytes. These fluorescent tracers have three important moieties: an olefin group for polymerization on anode surface so as to participate in SEI film formation during charge/discharge cycles, a polar group for Li-ion conduction, and an AIEgen for fluorescent tracing. Therefore, the tracers participate in SEI film-forming and result in a shining SEI film. This shining SEI film with intrinsic fluorescence signal allows direct observation and quantification on the distribution, relative abundance, and macro morphology of SEI. These fluorescent tracers can also reveal the SEI formation growth destruction regularity during charge/discharge cycles. Several summarized typical macro morphologies and evolution stages of SEI will enrich knowledge and understanding of SEI and help to gain insight into the interaction between electrolyte and anode, electrochemical performance, and cycle life of batteries.

Hybrid storage system management for hybrid electric vehicles under real operating conditions

This study proposes the use and management of hybrid storage systems to power hybrid electric vehicles with the aim of reducing the negative effects of high current values on battery cycling life. Findings derive from a case study on a commercial plug-in hybrid electric vehicle with battery pack operations supported by a Lithium-ion Capacitor module. Specific experimental laboratory activities focused on the parametrization and validation of an equivalent circuit model representing the behavior of Lithium-ion capacitors for integration into the overall vehicle model (designed calibrated and validated on the basis of data from on-board data acquisition and measurement systems). The simulation platform was used to test various energy management strategies for the hybrid storage system supplying the vehicle during real driving cycles characterized by different operating conditions and driving styles. Results highlight the benefits of using the considered management strategies in terms of battery durability, allowing performance comparison for different driving routes and styles.

Application of Theoretical Computational Simulations in Lithium Metal Batteries

In the area of high energy density batteries, lithium metal has attracted a lot of interest as an electrode material. But since lithium is so reactive, lithium metal batteries frequently have safety problems like thermal runaway, particularly under conditions such as overcharging, over-discharging, high temperatures, and mechanical impact. These safety issues can lead to dangerous situations such as battery explosion and fire. Furthermore, lithium-metal batteries are prone to dendrite development during the cycling process, which can pierce the separator and result in internal short-circuits, shortening the battery's cycle life. Lithium-metal battery use is strongly constrained by these important problems. To overcome these challenges, researchers are exploring various strategies, such as developing new electrolytes and additives, designing new battery structures, and exploring new anode materials. Computational simulations have emerged as a powerful tool to aid in this research. This review summarizes the recent applications of computational simulations in lithium metal batteries. Specifically, molecular dynamics (MD) and first-principles calculations have been widely employed to study key issues such as interface reactions, ion transport, and dendrite formation in lithium batteries. Additionally, this review discusses recent research directions in new types of ion electrolytes that can effectively address the safety concerns of lithium batteries and increase energy density, while still facing challenges in interface resistance and conductivity. The discussion of potential avenues for future research that will be pursued finishes this paper. These possibilities include multiscale simulations, the creation and manufacturing of new electrolyte materials, and the functional modification of lithium-metal anode surfaces.

Application of Nanomaterials in the Negative Electrode of Lithium-Ion Batteries

Li-ion batteries (LIBs) widely power modern electronics. However, there are certain limitations in the energy density, cycle life, and safety of traditional lithium-ion batteries, which restrict their further application and development. Therefore, new methods and technologies need to be explored to improve the performance stability of LIB. The emergence of nanomaterials provides new ideas and methods for the improvement of lithium-ion batteries. Nanomaterials have special structures and properties, and can improve the performance of LIB by regulating their morphology, size, and surface chemical properties. An overview of the development in research on using nanomaterials in LIB is given in this article. First, the features and benefits of nanomaterials were described, as well as the basic principles and development history of lithium-ion batteries. The use and performance of nanomaterials in lithium-ion batteries were then elaborated from a variety of angles, including nanosilicon, nanocarbon, and nanoiron oxide. Finally, the future applications of nanomaterials in lithium-ion batteries were prospected, and their development trends and challenges were pointed out. This article aims to provide a reference for the application of nanomaterials in lithium-ion batteries and promote further development in this field.

Nonflammable cosolvent enables methyl acetate-based electrolyte for 4.6 V-class lithium-ion batteries operating at −60 °C

The operational demands of electronic devices in extreme environments present a significant challenge for lithium-ion batteries (LIBs) to function effectively at low temperatures. To address this challenge, methyl acetate (MA) has been considered as a potential electrolyte solvent. However, MA-based electrolytes show poor compatibility with graphite anodes and high flammability, which affects battery cycle life and brings safety risks. Herein, an advanced non-flammable MA-based diluted highly concentrated electrolyte (DHCE) is designed incorporating ethoxy (pentafluoro) cyclotriphosphazene (PFPN) as a multifunctional diluent. The MA-based DHCE forms an anion-dominated solvation structure with improved thermodynamic stability. Moreover, PFPN synergizes with anions to form a protective LiF-rich solid electrolyte interphase (SEI), which effectively prevents continuous solvent decomposition. More importantly, PFPN can quench the free radical reaction and stop the spread of flames. This electrolyte enables LiNi0.65Co0.15Mn0.2O2 (NCM65)/graphite full cell to maintain 94.6 % capacity retention after 300 cycles at 1 C and −20 °C. Moreover, it allows NCM65/graphite full cell to operate at a high voltage of 4.6 V and −60 °C. This work demonstrates the importance of co-solvents for electrolyte design and provides new routes for the development of LIBs operating in harsh conditions.

An Intelligent Controller Based on Extension Theory for Batteries Charging and Discharging Control

The main purpose of this paper is to develop an intelligent controller for the DC-link voltage of bidirectional soft-switching converters used in the batteries with equalizing charge and discharge control. To accelerate the equalizing charge and discharge speed of batteries, the DC-link voltage controller of the bidirectional converters is designed based on extension theory. Firstly, the photovoltaic module arrays (PVMAs) are used with the intelligent maximum power point tracker (MPPT) for supplying the power to the load side. Through the bidirectional soft-switching converters, the PVMAs will be allowed to carry out the uniform charging and discharging for the storage battery in order to achieve the intended energy storage and auxiliary power supply functions. In terms of the controller design, the quantitative design techniques are utilized, by which the P-I controller parameters will be designed for the converter when attempting to achieve the same control performance at different working points. As a next step, the aforesaid parameters are used together with the extenics theory. Based on the variation in the output power of the bidirectional converter and that in the voltage of the storage battery, it allows the system to find out the intended P-I controller parameters that will be approximate to the prescribed control performance when operating under different working conditions. As a result, the P-I controller will be provided with more efficient control flexibility and control performances. Finally, actual test results demonstrated that the response time of the proposed intelligent extension controller is shortened by 3% compared to the quantitative design of the proportional–integral (P-I) controller. Based on the proposed quantitative design of an intelligent controller for uniform charging and discharging management of batteries, the sustainable utilization of renewable sources of energy can be improved. At the same time, the better economic benefit of the energy preservation system is obtained. In addition, it also prolongs the life cycle of batteries, and then enhances the reliability of the batteries.

Alkaline Ni-Zn Rechargeable Batteries for Sustainable Energy Storage: Battery Components, Deterioration Mechanisms, and Impact of Additives.

The demand for long-term, sustainable, and low-cost battery energy storage systems with high power delivery capabilities for stationary grid-scale energy storage, as well as the necessity for safe lithium-ion battery alternatives, has renewed interest in aqueous zinc-based rechargeable batteries. The alkaline Ni-Zn rechargeable battery chemistry was identified as a promising technology for sustainable energy storage applications, albeit a considerable investment in academic research, it still fails to deliver the requisite performance. It is hampered by a relatively short-term electrode degradation, resulting in a decreased cycle life. Dendrite formation, parasitic hydrogen evolution, corrosion, passivation, and dynamic morphological growth are all challenging and interrelated possible degradation processes. This review elaborates on the components of Ni-Zn batteries and their deterioration mechanisms, focusing on the influence of electrolyte additives as a cost-effective, simple, yet versatile approach for regulating these phenomena and extending the battery cycle life. Even though a great deal of effort has been dedicated to this subject, the challenges remain. This highlights that a breakthrough is to be expected, but it will necessitate not only an experimental approach, but also a theoretical and computational one, including artificial intelligence (AI) and machine learning (ML).

Integrated Optimal Energy Management and Sizing of Hybrid Battery/Flywheel Energy Storage for Electric Vehicles

This paper presents an integrated optimal Energy Management Strategy (EMS) and sizing of a high-speed Flywheel Energy Storage System (FESS) in a battery electric vehicle (EV). The methodology aims at extending the battery cycle life and drive range by relegating fast dynamics of the power demand to the FESS. For the EMS, the battery power and FESS energy are considered as weighted objectives of an optimization problem that are established using Pontryagin's Minimum Principle (PMP). In order to derive the optimal FESS size, the sizing algorithm is targeted to minimize the battery degradation level and increase the FESS energy interaction with the system. The performance of the proposed methodology is assessed using some driving cycles including ECE-15, UDDC, HWFET, and US06. Comparing the proposed battery/FESS to the battery-only topology, the battery SoH and life cycle are improved considerably for different driving cycles.

Thermal and aging performance characteristics of pouch-type lithium-ion battery using heat pipes under nonuniform heating conditions

Lithium-ion (Li-ion) batteries are excellent energy storage technologies for electric vehicles. However, the performance and life cycle of a battery can be degraded by extremely high temperatures under nonuniform heating conditions. This study aims to investigate the performance improvement of a battery thermal management system (BTMS) using heat pipes (HP) under various heat generation conditions. The cooling performances of the BTMS using aluminum plates (AP) and HP were compared by analyzing battery temperature and life cycle while varying the discharge rate (C-rate) from 1C to 5C and the ambient and liquid temperatures from 25 °C to 40 °C. Furthermore, the nonuniform heat ratio, defined as the heat ratio between the tab and bottom of the battery, was introduced to emulate the uneven temperature distribution, ranging from 1 to 3. The average temperature (Tavg) increases of AP and HP decreased by 22.7 % and 32 %, respectively, compared with that using natural convection (NC). HP showed a much lower maximum temperature (Tmax) and temperature difference (ΔT) of the battery than AP, owing to the effective heat transfer using the heat pipe. During cyclic operation, HP maintained stable Tmax and ΔT within 34.3 °C and 4 °C, respectively. As the nonuniform heat ratio increased, Tmax increased significantly, which was more severe in AP than in HP. HP exhibited up to a 41 % higher normalized performance index of Tmax than AP. Additionally, with the nonuniform heat ratio increasing from 1 to 3 at a C-rate of 5C, the ΔT of AP and HP increased by 7.6 °C and 4.4 °C, respectively. Finally, the normalized equivalent full cycles of AP and HP at a nonuniform heat ratio of 3 and a C-rate of 5C decreased by 4.3 % and 1.6 %, respectively, compared to their performance under uniform heat.

Cloud-Battery management system based health-aware battery fast charging architecture using error-correction strategy for electric vehicles

The health-aware battery fast charging (HABFC) strategy for electric vehicles (EVs) is predominantly dependent on the input conditions. These conditions are set using a set of various type of sensors (temperature, current, voltage, etc.), which can seldom be erroneous. Also, one of the primary challenges associated with physical battery management system (BMS) is the lack of memory required to execute intricate state estimation methodologies. Therefore, this paper proposes the Cloud-BMS based health-aware battery fast charging (HABFC) architecture with error correction strategy for reducing the charging time and increasing the cycle life of the EV battery. A cloud BMS has been integrated in the HABFC architecture to reduce the dependency on erroneous sensors. To design an effective cloud BMS, this paper reviews the seven most critical battery state estimation techniques (state of charge (SoC), state of health (SoH), state of power (SoP), state of energy (SoE), state of temperature (SoT), state of function (SoF), and state of safety (SoS)). Based on comparison of mathematical computational methods, its accuracy and challenges, the best computational method for each state estimation technique has been determined. The cloud BMS makes all state estimations based on parameters estimated using the virtual battery. Further, this paper presents an error correction strategy that helps correct the error in physical BMS employing a master-slave configuration. The proposed cloud BMS based HABFC architecture is validated using a cell cycling setup. It can be concluded that the proposed architecture produces 21.24% more cycle life as compared to fast charging without HABFC and 11% more cycle life as compared to cell charged using HABFC without cloud BMS.

Enabling Electrochemical-Mechanical Robustness of Ultra-High Ni Cathode via Self-Supported Primary-Grain-Alignment Strategy.

The electrochemical-mechanical degradation of ultrahigh Ni cathode for lithium-ion batteries is a crucial aspect that limits the cycle life and safety of devices. Herein, the study reports a facile strategy involving rational design of primary grain crystallographic orientation within polycrystalline cathode, which well enhanced its electro-mechanical strength and Li+ transfer kinetics. Ex situ and in situ experiments/simulations including cross-sectional particle electron backscatter diffraction (EBSD), single-particle micro-compression, thermogravimetric analysis combined with mass spectrometry (TGA-MS), and finite element modeling reveal that, the primary-grain-alignment strategy effectively mitigates the particle pulverization, lattice oxygen release thereby enhances battery cycle life and safety. Besides the preexisting doping and coating methodologies to improve the stability of Ni-rich cathode, the primary-grain-alignment strategy, with no foreign elements or heterophase layers, is unprecedently proposed here. The results shed new light on the study of electrochemical-mechanical strain alleviation for electrode materials.

Identifying the calendar aging boundary and high temperature capacity fading mechanism of Li ion battery with Ni-rich cathode

Temperature is well known to have a significant impact on the performance, safety, and cycle life of lithium-ion batteries. Increasing the operating temperature within the limits of safety and performance allowances facilitates the rapid acquisition of the capacity retention capability, enabling the construction of life prediction models. This paper combines the destructive and non-destructive analysis to determine the temperature boundary for LiNi0.8Co0.1Mn0.1O2 cathode based prismatic cells and clarify the aging mechanism of each component under high temperature calendar aging, which provides a great help for the experiment design in the actual application.