Impacts of Current Rates on the Degradation Behaviors of Lithium …
It is found that battery capacity experiences obvious degradation during over-discharge cycling, while the current rate is shown to have little impact on the degraded …
It is found that battery capacity experiences obvious degradation during over-discharge cycling, while the current rate is shown to have little impact on the degraded …
During the charging process of the battery pack, when a certain cell reaches the cutoff voltage, the battery pack is considered to be fully charged, and the discharge process is the same .
Firstly, the similarity of the charging voltage curves of the single cells within the battery pack is discussed with the help of the battery equivalent model and the aging test data. Ideally, the decline in battery capacity is reflected in the horizontal linear shrinkage of the charging voltage curve.
Capacity inconsistency is reflected in the curve shrinkage ratio, and SOC inconsistency and internal resistance inconsistency are reflected in the horizontal and vertical translation of the curve, respectively. Cell inconsistency is a crucial factor affecting the overall performance of the battery pack.
Pack 2 has a greater cell capacity difference of 24.37 Ah, about 20 % of the rated capacity. Such a large capacity difference is set to better verify the effectiveness and stability of the proposed method on battery packs with severe capacity inconsistency. Fig. 12. Cell capacities and initial capacities of the battery pack. (a) Pack 1 (b) Pack 2.
Ideally, the decline in battery capacity is reflected in the horizontal linear shrinkage of the charging voltage curve. However, considering the changes in OCV-SOC during the aging process and the influence of other complex aging factors, the charging voltage curve shows the characteristics of overall shrinkage and local deformation.
The available capacity of a battery pack is usually smaller than that of any single cell in the pack due to the cask effect caused by the inconsistency of the pack [46, 47].
It is found that battery capacity experiences obvious degradation during over-discharge cycling, while the current rate is shown to have little impact on the degraded …
This study investigates the effect of 50-kW (about 2C) direct current fast charging on a full-size battery electric vehicle''s battery pack in comparison to a pack exclusively charged at...
Importantly, there is an expectation that rechargeable Li-ion battery packs be: (1) defect-free; (2) have high energy densities (~235 Wh kg −1); (3) be dischargeable within 3 h; (4) have charge/discharges cycles greater …
Based on the results of the current study and the advantages of COMSOL Multiphysics in multiphysics field simulation, future work will focus on the influence of battery heating on the battery pack by adding heat-transfer fields to the existing pack model and exploring better methods to reduce the influence of temperature in terms of battery ...
Accurate estimation of battery pack capacity is crucial in determining electric vehicle driving range and providing valuable suggestions for battery health management. This article proposes an improved capacity co-estimation framework for cells and battery pack using partial charging process.
To widely commercialize electric vehicles (EVs), more efforts to improve their life span seem profoundly inevitable. Thermal conditions have profound the nonlinear effects on the degradation rate, performance, and safety level of an EV battery pack. In the current study, both cycle life and calendar life of a commercial LiFePO4-based cell are investigated …
Accurate estimation of battery pack capacity is crucial in determining electric vehicle driving range and providing valuable suggestions for battery health management. This …
Generally, a parallel battery module is referred to as "one large battery" because it is managed as a single entity by the battery management system (BMS) [10].The BMS monitors and controls the performance of the module; however, it can only measure the total current and temperature at a specific position within the module Owing to the high cost and …
Delayed charging improves battery life across multiple charging regimes. This study investigates the effect of 50-kW (about 2C) direct current fast charging on a full-size …
The results show that the inhomogeneity of cell current and discharge capacity in the pack with parallel modules connected in series can be improved by keeping each cell in a parallel module with the same distance to its module collector.
In the present study, a Li-ion battery pack has been tested under constant current discharge rates (e.g. 1C, 2C, 3C, 4C) and for a real drive cycle with liquid cooling. The experiments are ...
However, the effect of pulse charging on Li-ion batteries, charging time and service life of Li-ion batteries has always been a bottleneck in the application of electric vehicles [21].
The pulsed current has been proposed as a promising battery charging technique to improve the charging performance and maximize the lifetime for Lithium-ion (Li-ion) batteries. However, the effect ...
It is found that battery capacity experiences obvious degradation during over-discharge cycling, while the current rate is shown to have little impact on the degraded capacity within a unit cycle. Therefore, nearly all the over-discharged batteries present a linear degradation rate as the over-discharge cycling proceeds, 0.05%/cycle.
With the popularity of lithium-ion batteries, especially the widespread use of battery packs, the phenomenon of over-discharge may be common. To gain a better insight into over-discharge behavior, an experimental study is carried out in the present work to investigate the impact of current rate, i.e. cycle rate, charge rate and discharge rate on the degradation …
Increasing current increases losses due to heating, increasing the voltage means we can keep the heating losses fixed. It does though mean we need more cells in series and higher voltages brings other constraints once we …
Connecting batteries in parallel increases the current capacity and the overall amp-hour capacity. This setup lowers total resistance. On the other hand, connecting batteries in series increases the voltage but does not change the amp-hour capacity. For best results, batteries in series should have the same amp-hour rating.
The cell-to-pack concept, in other words building the cells directly into the battery pack without modules, has become established as a promising technology in order to increase the energy density at the pack level. This new battery design for passenger cars influences processes along the battery life cycle positively and negatively. Bertrandt …
However, high-power charging may negatively affect the durability and safety of lithium batteries because of increased heat generation, capacity fading, and lithium plating, …
However, high-power charging may negatively affect the durability and safety of lithium batteries because of increased heat generation, capacity fading, and lithium plating, which can induce the risk of battery thermal runaway.
Based on the results of the current study and the advantages of COMSOL Multiphysics in multiphysics field simulation, future work will focus on the influence of battery heating on the battery pack by adding heat-transfer fields …
Increasing current increases losses due to heating, increasing the voltage means we can keep the heating losses fixed. It does though mean we need more cells in series and higher voltages brings other constraints once …
Delayed charging improves battery life across multiple charging regimes. This study investigates the effect of 50-kW (about 2C) direct current fast charging on a full-size battery electric vehicle''s battery pack in comparison to a pack exclusively charged at 3.3 kW, which is the common alternating current Level 2 charging power level.
With the development of battery technology, large-scale battery applications are increasing. In order to obtain a higher current and voltage level and improve the overall energy efficiency, batteries are connected in series and parallel. Bulk model is the most used model to simulate battery packs, and the simulation results of single cell are enlarged several times to …
With the proposed algorithm, Monte Carlo simulations were evaluated to obtain the influence of battery series and parallel number and normal distribution parameters on current distribution. Simulation results show that an increase in the number of series will reduce the inconsistency of the current distribution, and an increase in the number of ...
This study investigates the effect of 50-kW (about 2C) direct current fast charging on a full-size battery electric vehicle''s battery pack in comparison to a pack exclusively charged at...
Above all, battery models are critical in developing accurate algorithms for battery state estimation, such as state of health (SOH) and state of charge (SOC), of working battery packs [11]. Model predictions are commonly executed within an embedded battery management system (BMS) to provide a high-efficiency estimation method, which ensures …
Connecting batteries in parallel increases the current capacity and the overall amp-hour capacity. This setup lowers total resistance. On the other hand, connecting batteries …
With the proposed algorithm, Monte Carlo simulations were evaluated to obtain the influence of battery series and parallel number and normal distribution parameters on …
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