scholarly journals Cell Replacement Strategies for Lithium Ion Battery Packs

Batteries ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 39
Author(s):  
Nenad G. Nenadic ◽  
Thomas A. Trabold ◽  
Michael G. Thurston
Keyword(s):  
Lithium Ion Battery ◽  
Early Life ◽  
Coulombic Efficiency ◽  
Single Cells ◽  
Lithium Ion ◽  
Battery Pack ◽  
Battery Life ◽  
Cell Replacement ◽  
Battery Systems ◽  
Battery Packs

The economic value of high-capacity battery systems, being used in a wide variety of automotive and energy storage applications, is strongly affected by the duration of their service lifetime. Because many battery systems now feature a very large number of individual cells, it is necessary to understand how cell-to-cell interactions can affect durability, and how to best replace poorly performing cells to extend the lifetime of the entire battery pack. This paper first examines the baseline results of aging individual cells, then aging of cells in a representative 3S3P battery pack, and compares them to the results of repaired packs. The baseline results indicate nearly the same rate of capacity fade for single cells and those aged in a pack; however, the capacity variation due to a few degrees changes in room temperature (≃±3 ∘ C) is significant (≃±1.5% of capacity of new cell) compared to the percent change of capacity over the battery life cycle in primary applications (≃20–30%). The cell replacement strategies investigation considers two scenarios: early life failure, where one cell in a pack fails prematurely, and building a pack from used cells for less demanding applications. Early life failure replacement found that, despite mismatches in impedance and capacity, a new cell can perform adequately within a pack of moderately aged cells. The second scenario for reuse of lithium ion battery packs examines the problem of assembling a pack for less-demanding applications from a set of aged cells, which exhibit more variation in capacity and impedance than their new counterparts. The cells used in the aging comparison part of the study were deeply discharged, recovered, assembled in a new pack, and cycled. We discuss the criteria for selecting the aged cells for building a secondary pack and compare the performance and coulombic efficiency of the secondary pack to the pack built from new cells and the repaired pack. The pack that employed aged cells performed well, but its efficiency was reduced.

Thermal Management of Air-Cooling Lithium-Ion Battery Pack

2021 ◽  
Vol 38 (11) ◽  
pp. 118201
Author(s):  
Jianglong Du ◽  
Haolan Tao ◽  
Yuxin Chen ◽  
Xiaodong Yuan ◽  
Cheng Lian ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Thermal Management ◽  
Thermal Performance ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Battery Pack ◽  
Cooling Effect ◽  
Air Cooling ◽  
Safety Issues ◽  
Battery Packs

Lithium-ion battery packs are made by many batteries, and the difficulty in heat transfer can cause many safety issues. It is important to evaluate thermal performance of a battery pack in designing process. Here, a multiscale method combining a pseudo-two-dimensional model of individual battery and three-dimensional computational fluid dynamics is employed to describe heat generation and transfer in a battery pack. The effect of battery arrangement on the thermal performance of battery packs is investigated. We discuss the air-cooling effect of the pack with four battery arrangements which include one square arrangement, one stagger arrangement and two trapezoid arrangements. In addition, the air-cooling strategy is studied by observing temperature distribution of the battery pack. It is found that the square arrangement is the structure with the best air-cooling effect, and the cooling effect is best when the cold air inlet is at the top of the battery pack. We hope that this work can provide theoretical guidance for thermal management of lithium-ion battery packs.

scholarly journals Estimation of SOC Inconsistencies in Lithium-ion Battery Packs Based on Battery Pack Modeling and Clustering Algorithm

2020 ◽  
Vol 56 (18) ◽  
pp. 154
Author(s):  
XIANG Zhaojun ◽  
HU Fengling ◽  
LUO Minghua ◽  
FANG Chongquan ◽  
HU Xiaosong
Keyword(s):  
Lithium Ion Battery ◽  
Clustering Algorithm ◽  
Lithium Ion ◽  
Battery Pack ◽  
Battery Packs

Lithium-Ion Battery Packs Formation With Improved Electrochemical Performance for Electric Vehicles: Experimental and Clustering Analysis

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Liu Yun ◽  
Jayne Sandoval ◽  
Jian Zhang ◽  
Liang Gao ◽  
Akhil Garg ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
Electric Vehicles ◽  
Clustering Analysis ◽  
Lithium Ion ◽  
Internal Resistance ◽  
Battery Pack ◽  
Self Organizing Map ◽  
Battery Packs

With the increase of production of electrical vehicles (EVs) and battery packs, lithium ion batteries inconsistency problem has drawn much attention. Lithium ion battery imbalance phenomenon exists during three different stages of life cycle. First stage is premanufacturing of battery pack i.e., during the design, the cells of similar performance need to be clustered to improve the performance of pack. Second is during the use of battery pack in EVs, batteries equalization is necessary. In the third stage, clustering of spent lithium ion batteries for reuse is also an important problem because of the great recycling challenge of lithium batteries. In this work, several clustering and equalization methods are compared and summarized for different stages. The methods are divided into the traditional methods and intelligent methods. The work also proposes experimental combined clustering analysis for new lithium-ion battery packs formation with improved electrochemical performance for electric vehicles. Experiments were conducted by dismantling of pack and measurement of capacity, voltage, and internal resistance data. Clustering analysis based on self-organizing map (SOM) neural networks is then applied on the measured data to form clusters of battery packs. The validation results conclude that the battery packs formed from the clustering analysis have higher electrochemical performance than randomly selected ones. In addition, a comprehensive discussion was carried out.

Optimization of charging strategy for lithium-ion battery packs based on complete battery pack model

2021 ◽  
Vol 37 ◽  
pp. 102466
Author(s):  
Yunjian Li ◽  
Kuining Li ◽  
Yi Xie ◽  
Bin Liu ◽  
Jiangyan Liu ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Lithium Ion ◽  
Battery Pack ◽  
Battery Packs ◽  
Charging Strategy

scholarly journals Reliability Modeling Method for Lithium-ion Battery Packs Considering the Dependency of Cell Degradations Based on a Regression Model and Copulas

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1054 ◽  
Author(s):  
Lizhi Wang ◽  
Yusheng Sun ◽  
Xiaohong Wang ◽  
Zhuo Wang ◽  
Xuejiao Zhao
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
Electric Drive ◽  
Large Scale ◽  
Lithium Ion ◽  
Degradation Process ◽  
Battery Pack ◽  
Reliability Model ◽  
Dependent Relationship ◽  
Battery Packs

Lithium-ion batteries are widely used as basic power supplies and storage units for large-scale electric drive products such as electric vehicles. Their reliability is directly related to the life and safe operation of the electric drive products. In fact, the cells have a dependent relationship with the degradation process and they affect the degradation rate of the entire battery pack, thereby affecting its reliability. At present, most research focuses on the reliability of battery packs and assumes that their cells are independent of each other, which may cause the reliability of the evaluation to deviate greatly from the actual level. In order to accurately assess the reliability of lithium-ion batteries, it is necessary to build a reliability model considering the dependency among cells for the overall degradation of lithium-ion battery packs. Therefore, in this study, based on a lithium-ion battery degradation test, the Wiener process is used to analyze the reliability of four basic configurations of lithium-ion battery packs. According to the degradation data of the battery packs, the Copula function is used to quantitatively describe the dependent relationship in the degradation process of a single battery, and the quantitative dependent relationship is combined with the reliability model to form a new reliability model. Finally, taking the battery system of Tesla S as an example, a feasible optimization method for battery pack design is provided based on the model constructed in this work.

scholarly journals Lithium-Ion Battery Life Model with Electrode Cracking and Early-Life Break-in Processes

2021 ◽  
Author(s):  
Kandler Smith ◽  
Paul Gasper ◽  
Andrew M. Colclasure ◽  
Yuta Shimonishi ◽  
Shuhei Yoshida
Keyword(s):  
Lithium Ion Battery ◽  
Early Life ◽  
Lithium Ion ◽  
Battery Life ◽  
Life Model

scholarly journals A Framework of Multilayer Multiphase Interleaved Converter for Electric Vehicle Based on Graph Theory

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Bochao Yang ◽  
Pinduan Hu ◽  
Teng Li ◽  
Dawei Song ◽  
Zhifei Shan ◽  
...  
Keyword(s):  
Graph Theory ◽  
Energy Storage ◽  
Lithium Ion Battery ◽  
Large Scale ◽  
Lithium Ion ◽  
Battery Pack ◽  
Equilibrium System ◽  
Important Indicator ◽  
Average Efficiency ◽  
Battery Packs

Lithium-ion batteries play an important role in large-scale energy storage systems. However, the power inconsistency of the battery packs restricts the developments of modern technologies in energy storage area. The motivation of the present study is to serve the growing needs of the energy balance for lithium-ion battery packs. The present study proposes a flexible multiphase interleaved converter for the energy equalization of a lithium battery pack with series configuration. Moreover, the graph theory is applied to the analysis of equalization circuits. It is intended to establish a unified standard for the comparison. The parameter of average efficiency is considered as an important indicator to evaluate the characteristics of the equilibrium system. The proposed method is verified by constructing a lithium-ion battery pack with the equalization circuit. It is observed that the proposed multiphase interleaved converter has flexible characteristics, while it has low energy loss compared with the conventional methods. It is found that the proposed method simplifies the complex equalization circuits into graphs and facilitates the comparison of the average efficiency of the system. It is concluded that this method is a feasible and powerful method for evaluating the battery equalization circuit. This approach can be applied for solving complex problems in other engineering applications.

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