Service Life Of Battery Research Articles

Performance Benchmarking of Active-Front-End Rectifier Topologies Used in High-Power, High-Voltage Onboard EV Chargers

High power onboard battery chargers employed in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs) fed from three-phase mains typically consist of a two-stage structure as AC-DC and DC-DC stages. The AC-DC stage is also known as the active front end (AFE). While the AFE rectifies the mains voltage, maintains the power factor, and provides a constant DC-link voltage to the DC-DC converter, the DC-DC converter stage regulates the charging current considering the charging algorithms in order to extend the battery service life. This study focuses on the selection of cost/performance effective AFE topology that can be used in high power onboard chargers. Four different suitable AC-DC topologies are investigated: (i) 3-phase 2-level rectifier, (ii) 3-phase, 3-level neutral-point-clamped (NPC) rectifier, (iii) 3-phase, 3-level T-type rectifier, and (iv) Vienna rectifier. In this study, the aforementioned AFE topologies have been simulated on the PLECS/SpeedFit environment and compared in terms of efficiency, losses, temperature, the number of switching elements, cost and cost/efficiency metrics. The performance results of the aforementioned topologies have been evaluated under different operating frequencies. The results reveal that the most suitable topology alternatives for the front-end AC-DC converter are 3-phase 2-level PWM rectifier and Vienna rectifier. Although the 3-phase 2-level PWM rectifier is superior with its 12% cost advantage, fewer components, and ease of control advantages, it lags a little behind the Vienna rectifier in terms of total harmonic distortion.

Electric/thermal hybrid energy storage planning for park-level integrated energy systems with second-life battery utilization

The use of retired batteries from electric vehicles as a second-life battery energy storage system has been recognized as a way to break the high investment cost limitation of battery energy storage systems with the associated cost reduction of a park-level integrated energy system. The battery degradation and replacements should be further considered in the planning period, especially compared with new battery energy storage systems. Additionally, there is a lack of discussion on utilizing thermal energy storage systems in coordination with second-life battery to reduce degradation. For this reason, an electric/thermal hybrid energy storage system planning method for park-level integrated energy systems with second-life battery utilization is proposed. A cumulative battery life loss calculation model is developed. A bi-level optimal planning model of electric/thermal hybrid energy storage system using second-life batteries, including an upper-level planning model and a lower-level operating model, is proposed. At the upper level, to maximize the net present value during the planning stage, the capacity of the hybrid energy storage system as well as when the second-life battery energy storage system needs to be replaced are optimized. At the lower level, the operation schemes are optimized to obtain the minimum annual operating cost, which are fed back to the upper level. The proposed method considers continuous capacity degradation of second-life batteries and mutually beneficial relationships between thermal energy storage and second-life batteries. Finally, a case study demonstrates the economic effectiveness and battery service life improvement of the proposed planning method.

A Multiphysics System-to-Cell Framework to Assess the Impact of Operating Conditions of Standalone PV Systems on Lithium-Ion Battery Lifetime

This paper proposes a multiphysics simulation structure for predicting Li-ion batteries’ useful life by consolidating battery cell electrochemical and thermal-aging models into the electrical domain of PV-battery standalone systems. This model can consider the effect of operating conditions at the system level, such as charge/discharge patterns and energy management strategies, to evaluate battery capacity fade at the cell level. The proposed model is validated using experimental observations with a RRMSE of 1.1%. Results show that the operating conditions of the battery bank affect its lifetime significantly. A wide range of 2.7 to 12.5 years of battery lifetime is predicted by applying the model to different case studies. In addition, the model predicts that managing the maximum cell state of charge level can enhance the battery bank lifetime by 60%. The developed model is a generic multiscale decision-making framework to investigate the effect of operating conditions on battery service life.

Charging balance management for automotive battery in low-voltage power network under low temperature conditions and at deep discharge of the automotive battery in the car

The paper presents the results of theoretical analysis and mathematical modeling and implementation of algorithms for controlling the charging balance of battery in a low-voltage power network at low temperatures and at deep discharge of the battery as part of an intelligent vehicle control system with a combined power unit. The target of the research is to develop methods to prevent the critical discharge of the battery, methods of charging the battery and methods for control of the current state of the automotive battery. Experiments were performed, experimental data and graphs were obtained. The results of the research allow performing adjustment of the rechargeable battery charge balance management model and contribute to improving the energy balance of the grid, increasing the efficiency and service life of batteries.

A balancing control method by considering lithium batteries state of charge

In order to quickly and accurately reduce the inconsistency of charge between lithium battery and prolong the service life of lithium battery, a balancing control method for lithium batteries state of charge (SOC) is proposed in this paper. The difference of each adjacent battery pack in the series lithium batteries and the difference of each adjacent battery pack in each monomer lithium battery are used as the equalization criteria, a bi-directional energy flow topology circuit is constructed using inductor as energy storage element. The magnitude and direction of the equalization current are controlled, and the balancing control of the whole lithium batteries is finally realized by controlling the on-off time of the Mosfet tube. Compared with the traditional extreme difference control method, the simulation results show that the two-level layered balancing control method proposed in this paper increases the rapidity of static and random currents by 23% and 17.1% respectively, and the accuracy increases by 13.3%. The proposed control approach can be provided with equalization efficiency highly, and give some advice for servicing lithium battery application.

The impact of climate policy implementation on lithium, cobalt and nickel demand: The case of the Dutch automotive sector up to 2040

The Dutch national climate agreement (‘Klimaatakkoord’), stipulates a 49% decrease in greenhouse gas (GHG) emissions by 2030, relative to the 1990 level. To accommodate this target, the passenger vehicles sector must reduce its GHG emissions by 30% in 2030, which likely will come about by replacing internal combustion engine vehicles with electric vehicles. In this study, a dynamic material flow model combined was applied to investigate the future demand for (and metabolism of) lithium, cobalt, and nickel within various scenarios of Dutch electric vehicle markets stemming from climate policy implementation. Our results show that by 2040 the demand for electric vehicles rapidly grows by an order of magnitude, which expands by two orders of magnitude the annual accumulation of these metals in the Netherlands when compared to the 2019 levels. Lithium and nickel demand will keep increasing through 2040, while the demand trend of cobalt will start to drop after 2030, due to changes in battery technology. Increasing the EV driving range and replacing EV batteries during an EV lifetime will increase the demand for these metals by 10%–19%. Conversely, extending the average battery lifetime to meet the vehicle lifetime could reduce the demand of these metals by 30%. Due to the low open-loop recycling of these metals, policies must seek to minimize their presence in the electric mobility sector, while also stimulating better recycling practices and infrastructure. • The demand for electric vehicles (EV) and Li, Co and Ni used in the EV batteries will be accelerated under the promotion of the Dutch climate policy. • The innovation in battery cathode technology is one of the factors to diversify the requirements of raw materials. • The extension of battery service life is important to lessen the demand for primary materials.

Adaptive parameter optimal energy management strategy based on multi-objective optimization for range extended electric vehicle

With the aim of economy improvement, emission reduction and prolonging the battery service life, an adaptive parameter optimal energy management strategy is proposed for range extended electric vehicle and a method of multi-objective optimization (MOO) is proposed. Firstly, two strategies based on different threshold parameter types, namely velocity-switch-based multi-operation-point control strategy (MCS v–b) and power-switch-based multi-operation-point control strategy (MCS p–b) are designed. Then, the oil-electric conversion loss rate, comprehensive exhaust emission, and battery capacity loss rate are selected as the optimization objectives. The barebones multi-objective particle swarm optimization is applied in MCS v–b and MCS p–b for solving the MOO problem. The simulation results show a clear conflict that three optimization objectives cannot be optimal under the same solution. And then, the individual with optimal comprehensive objective is taken as the final optimization solution to evaluate the performance of the proposed methodology. As expected, the proposed MCS p–b has a positive effect on prolonging the battery service life while ensuring high fuel economy and low emission. Experimental test results thoroughly validate the proposed approach and this result can be used to improve comprehensive performance levels.

Service life tests for storage batteries used in islanded power systems with renewable energy sources

We investigated the service life of storage batteries to provide recommendations on the design of energy storage systems used in islanded energy systems based on renewable power sources. The service life of maintenance-free, sealed lead-acid batteries produced by absorbed glass mat (AGM) technology was determined by endurance tests carried out by repeated charge/discharge cycles according to specified load profiles, implemented at a specialized Chroma Test System station. Three battery load profiles were simulated: one for the standard DC charge/discharge mode, and two for the charge/discharge modes from renewable energy sources. To this end, the actual data obtained from monitoring the operating modes of a wind power plant were used. It was found that the battery service life depends on the intensity of stress factors. Among them, the throughput factor has the most pronounced influence on the battery lifespan. To extend the service life of storage batteries, it is proposed to separate the charge/discharge modes in time. For batteries operated on renewable energy profiles, this approach decreases time intervals between full charges and at low battery levels, which increases the battery service life by 14%. A solution to designing an energy storage system for microgrids was proposed, which consists in the use of a combined double-circuit energy storage unit. An experimental prototype of such a unit with a power of 15 kW was developed. The use of a combined energy storage unit in the microgrid system: increases the battery service life by 20–30% compared to analogues; improves the static and dynamic stability of the local energy system with a response time of no more than 50 ms towards power change; allows a fuel replacement level of at least 25%; reduces the electricity cost by 25–30%.

Time-frequency analysis of the spatial distribution for Li<sup>+</sup>concentration in the electrolyte throughout the full battery

<p indent=0mm>Advanced battery management systems can improve the safety, operation efficiency, and service life of the power Li-ion battery. Such a battery management system requires accurate information about the spatial distribution of Li⁺ concentration in the electrolyte. In general, the acquisition of the spatial distribution information of Li⁺ concentration can be described based on the Li battery physicochemical model and its corresponding solution algorithm. In this study, a pseudo-2D electrochemical model is used as the Li battery physicochemical model, which can provide complete information about the spatial distribution of Li⁺ concentration in the electrolyte throughout the full battery. Regarding the solution algorithm, which normally takes considerable time for the traditional finite difference method to discretize the diffusion partial differential equation, a new algorithm combining the finite element and <italic>θ</italic> method is proposed and a simple and efficient linear basis function is introduced into the finite element method in this study, thus aiming at a quick calculation on the spatial distribution of Li⁺ concentration in the electrolyte throughout the complete battery under different charging/discharging modes. The results of numerical calculation show: (1) in the frequency domain, the numerical solution obtained by the finite element method is highly consistent with the analytical solution obtained by the variation-of-parameters method; (2) in the time domain, the numerical solution obtained by the combination of finite element method and <italic>θ</italic> method agrees well with that obtained by the finite difference method. The algorithm proposed in this paper provides a new method for obtaining the spatial distribution of Li⁺ concentration in the electrolyte throughout the full battery with high speed and accuracy.

Microstructure and properties of 6061/2A12 dissimilar aluminum alloy weld by laser oscillation scanning

The development of high-power galvanometer provides a new way to solve Low weld strength of dissimilar aluminum alloy in the packaging of new energy power batteries. The effect of laser scanning frequency and amplitude on microstructure and properties of 6061/2A12 dissimilar aluminum alloy weld was studied in this paper. Scanning electron microscope (SEM), X-ray diffraction (XRD) and electron backscatter diffraction pattern (EBSD) were used to detect the microstructure morphology, composition and distribution of the weld. The results showed that increasing laser scanning frequency and amplitude was beneficial to increase the proportion of equiaxed grains in fusion zone and decrease the average diameter of equiaxed grains. The reason was that stirring action of scanning beam increased the heterogeneous nucleated particles in molten pool. The tensile test showed that scanning laser can't increase the hardness and tensile strength, but it was beneficial to increase the elongation, and the maximum is 120% higher than that of non-scanning weld. By increasing the scanning frequency and amplitude, the fracture location of weld gradually changed from fusion zone to the heat-affected zone. The analysis showed that scanning laser makes Cu element in the weld evenly distributed, and the θ-Al2Cu phase and s-Al2CuMg strengthening phase increase, which increased the strength of weld fusion zone. The research results provide a new way to improve the packaging strength, safety and service life of new energy power batteries.

A joint grey relational analysis based state of health estimation for lithium ion batteries considering temperature effects

A reliable and efficient state-of-health (SOH) estimation is essential to prolong service life of lithium-ion batteries (LIBs), optimize power management strategies and reduce cost. In this paper, a joint grey relational analysis (JGRA) based SOH estimation method considering temperature effects is proposed to explore the degradation mechanism of LIBs at different temperature and a generic temperature regressive model is developed. JGRA is used to calculate joint grey correlation degree (JGCD) of the incremental capacity (IC) curves of aged batteries to fresh battery due to their geometric proximity. Experiments including life cycle tests and capacity tests are conducted on three lithium cobalt batteries at different temperatures to verify the performance of the proposed method. The results show that the proposed method can evaluate SOH of LIBs at different temperatures within 2.41% error bound.

A Critical Review of Online Battery Remaining Useful Lifetime Prediction Methods

Lithium-ion batteries play an important role in our daily lives. The prediction of the remaining service life of lithium-ion batteries has become an important issue. This article reviews the methods for predicting the remaining service life of lithium-ion batteries from three aspects: machine learning, adaptive filtering, and random processes. The purpose of this study is to review, classify and compare different methods proposed in the literature to predict the remaining service life of lithium-ion batteries. This article first summarizes and classifies various methods for predicting the remaining service life of lithium-ion batteries that have been proposed in recent years. On this basis, by selecting specific criteria to evaluate and compare the accuracy of different models, find the most suitable method. Finally, summarize the development of various methods. According to the research in this article, the average accuracy of machine learning is 32.02% higher than the average of the other two methods, and the prediction cycle is 9.87% shorter than the average of the other two methods.

Superior cycling stability of H0.642V2O5·0.143H2O in rechargeable aqueous zinc batteries

To increase the service life of rechargeable batteries, transition metal oxide hosts with high structural stability for the intercalation of carrier ions are important. Herein, we reconstruct the crystal structure of a commercial V2O5 by pre-intercalating H+ and H2O pillars using a facile hydrothermal reaction and obtain a bi-layer structured H0.642V2O5·0.143H2O (HVO) as an excellent host for aqueous Zn-ion batteries. Benefiting from the structural reconstruction, the irreversible “layer-to-amorphous” phase evolution during cycling is considerably less, resulting in ultra-high cycling stability of HVO with nearly no capacity fading even after 500 cycles at a current density of 0.5 A g−1. Moreover, a synthetic proton and Zn2+ intercalation mechanism in the HVO host is demonstrated. This work provides both a facile synthesis method for the preparation of V-based compounds and a new viewpoint for achieving high-performance host materials.

Techno-economic performance analysis of synergistic energy sharing strategies for grid-connected prosumers with distributed battery storages

Renewable energy planning, electrochemical storages, and prosumer-based energy management and sharing in smart grids are critical elements for the transition towards carbon neutrality, whereas the synergistic effects between distributed renewables and storages have not been sufficiently investigated regarding spatiotemporal compensation between energy supply and demand. Moreover, the economic benefits of individual prosumers need to be quantified to motivate their participation in the sharing scheme. In this study, a peer-to-peer (P2P) energy sharing paradigm was formulated, consisting of hybrid solar-wind renewable systems, battery storages, grid-connected commercial prosumers (a high-rise office building and a high-rise hotel), and flexible energy management. Different sharing scenarios with/without storage sharing were studied for performance improvements. Case studies show that, compared to the traditional peer-to-grid operation, the proposed P2P sharing operation with storage sharing can promote the self-consumption from 0.591 to 0.795 and reduce the net cost from 80.4 to 52.7 HKD/m2·a by 34.5%. The formulated energy sharing strategies can also contribute to energy bill savings for each prosumer when considering the profit from transactive energy and grid feed-in tariff, whereas the storage sharing may shorten the battery service life. The research can provide synergistic sharing strategies, energy planning, and economic policy guidelines to achieve carbon-neutral communities.

ANALYSIS OF THE POSSIBILITY OF USING BATTERIES OF THE LATEST TECHNOLOGIES ON SAMPLES OF ARMORED WEAPONS AND MILITARY EQUIPMENT

The subject matter of the article is mass and dimensional characteristics of batteries, their design, electrical, operational parameters and energy capabilities. The goal of the study is the possibility of using maintenance-free batteries on samples of armored weapons and military equipment. The tasks to be solved are: to analyze the existing technologies for the batteries production, their advantages and disadvantages given the peculiarities of the operation of military equipment and the main technical characteristics of the batteries; by statistical data processing to investigate the dependences of “starter” discharge modes and energy capabilities of the batteries manufactured by technologies of different generations; to investigate the possibilities of constructive implementation of power supply formation taking into account possible design changes in the engine starting system, ensuring the necessary charge stability and compensation for exceeding the cost of gel and Absorbed in Glass Mat (AGM) batteries in comparison with the cost of the type 12ST85 ones. General scientific and special methods of scientific knowledge are used. The following results were obtained: The existing technologies of battery production, their advantages and disadvantages have been analyzed taking into account the peculiarities of the operation of military equipment and the main technical characteristics of batteries. The dependences of the “starter” discharge modes and the energy capabilities of batteries made by different technologies generations have been studied. Possibilities of constructive realization of power supply formation taking into account available constructive changes in the engine electric start system, providing the necessary charge stability and compensation for excess cost of gel and AGM batteries compared to the cost of batteries type 12ST85 have been investigated. Conclusions. Using at the samples of armored vehicles and military equipment batteries made by modern technology does not require fundamental structural changes in the electrical equipment of the machine. To meet the requirements of the standards for voltage parameters in the on-board armored weapons and military equipment networks, it is necessary to install an appropriate voltage relay regulator. The issue of exceeding the cost of gel and AGM batteries compared to the cost of type 12CT-85 ones can be compensated by the absence of costs for operating materials, maintenance personnel as well as the long service life of gel or AGM batteries compared to conventional lead-acid ones.

Free-standing films based on Ni wires core/foamed NiO shell as hosts for stable lithium anodes

Due to the stable three-dimensional (3D) conductive skeleton and superior lithiophilic surface, lithiophilic 3D conductive network structures are considered as excellent hosts for lithium metal batteries. How to efficiently construct unique lithiophilic 3D conductive structures as stable hosts for lithium metal anodes remains a challenge in the realistic applications. Herein, three-dimensional free-standing films based on Ni wires core/foamed NiO shell (Ni@NiO) are successfully fabricated as stable hosts for lithium metal anodes. The as-designed unique structures can effectively alleviate the large volume expansion and suppress lithium dendritic growth during the charge/discharge reaction, which can improve the service life of lithium metal batteries. The symmetric batteries of as-prepared Li-Ni@NiO-400 anodes deliver superior electrochemical performance, retaining a flat and stable voltage profiles with 13 mV for 2020 h at a current density of 1.0 mA cm−2. Simultaneously, the as-assembled LiFePO4/Li-Ni@NiO-400 full cells exhibit superior rate capability (~104.4 mAhg−1 at 10C) and 93.8% retention capacity after 500 cycles at the rate of 1C (0.012% decay per cycle). Above all, the unique 3D structure with as-designed free-standing films based on Ni wires core/foamed NiO shell structure and its design strategy hold a significant potential for the development of high energy-dense and stable metal batteries.

RESEARCH ON POLICIES OF POWER BATTERIES RECYCLE IN CHINA FROM THE PERSPECTIVE OF LIFE CYCLE

As fueled by the rapid advancement of novel energies-based vehicles in our nation since 2015, Chinese production and ownership of novel energies-based vehicles in China have been leaping forward. According to 4—8 years’ service life of power batteries, China ushered into the large-scale scrapping phase of power batteries in 2019, so the power batteries recycle system should be urgently constructed. Given the life cycle perspective, the characteristics of each stage of the power battery life cycle are analyzed in the present study. As revealed from the results, the upstream end of the power batteries recycle system in China is not yet perfect, the production capacity at the midstream end tends to be excess, and the downstream end is in the exploratory phase. Moreover, the present study analyzes the policies throughout the life cycle of power batteries, and it is reported that the recycling policies at the midstream processing end are relatively concentrated, the upstream and downstream policies are comparatively deficient, the top-level legal construction is lacked, the recycling network is not perfect, and the incentive and guidance policies for echelon exploitation enterprises require modification, and relevant policy suggestions are proposed.

Synthetic state of charge estimation for lithium-ion batteries based on long short-term memory network modeling and adaptive H-Infinity filter

Accurate state of charge estimation is essential to improve operation safety and service life of lithium-ion batteries. This paper proposes a synthetic state of charge estimation method for lithium-ion batteries based on long short-term memory network modeling and adaptive H-infinity filter. Firstly, the long short-term memory network is exploited to roughly estimate state of charge with the input of voltage, current, operating temperature and state of health. Then, to mitigate the output fluctuation and improve the estimation robustness of long short-term memory network, the adaptive H-infinity filter is employed to flatten the estimation results and further improve the estimation accuracy. A main advantage of the proposed synthetic method lies in that precise battery modeling and burdensome model parameter identification tasks that are imperative in traditional observers or filters can be omitted, thus improving the application efficiency of the proposed algorithm. The proposed method is verified effective on two types of lithium-ion batteries under dynamic working scenarios including the varying temperature and aged conditions. The experimental results highlight that the estimation error of state of charge can be restricted within 2.1% in wide temperature range and different aging states, manifesting its high-precision estimation capacity and strong robustness.

Improved SSD-assisted algorithm for surface defect detection of electromagnetic luminescence

Defect detection of electromagnetic luminescence (EL) cells is the core step in the production and preparation of solar cell modules to ensure conversion efficiency and long service life of batteries. However, due to the lack of feature extraction capability for small feature defects, the traditional single shot multibox detector (SSD) algorithm performs not well in EL defect detection with high accuracy. Consequently, an improved SSD algorithm with modification in feature fusion in the framework of deep learning is proposed to improve the recognition rate of EL multi-class defects. A dataset containing images with four different types of defects through rotation, denoising, and binarization is established for the EL. The proposed algorithm can greatly improve the detection accuracy of the small-scale defect with the idea of feature pyramid networks. An experimental study on the detection of the EL defects shows the effectiveness of the proposed algorithm. Moreover, a comparison study shows the proposed method outperforms other traditional detection methods, such as the SIFT, Faster R-CNN, and YOLOv3, in detecting the EL defect.

Study on the technical and economic feasibility of echelon use of waste power batteries used in new energy vehicles in China

The echelon use of power batteries is considered as an efficient recycling method which can effectively extend the service life of power batteries and reduce costs. The echelon use of power batteries is encouraged by national policies and widely concerned in the industry so it has quickly became a hot spot among the issue about industry development. This article compares and analyzes the battery standard requirements for power batteries and the intended application fields of echelon use and the economics of using lead-acid batteries and decommissioned power batteries in different application fields. This article initially draws the conclusions about the technical and economic feasibility of echelon use of power batteries.