Experimental Study on Thermal Runaway Process of 18650 Lithium-Ion Battery under Different Discharge Currents

Lithium-ion batteries (LIBs) subjected to external heat may be prone to failure and cause catastrophic safety issues. In this work, experiments were conducted to investigate the influence of discharge current on the thermal runaway process under thermal abuse. The calibrated external heat source (20 W) and discharge currents from 1 to 6 A were employed to match the thermal abuse conditions in an operational state. The results indicated that the key parameters during the failure process, such as the total mass loss, the onset temperatures of safety venting and thermal runaway, and the peak temperature, are ultimately determined by the capacity inside the battery, and the discharge current can hardly change it. However, discharge currents can produce extra energy to accelerate the thermal runaway process. Compared with the battery in an open circuit, the onset time of thermal runaway was reduced by 7.4% at 6 A discharge. To quantify the effect of discharge current, the total heat generation by discharge current was calculated. The results show that a heat generation of 1.6 kJ was produced when the battery was discharged at 6 A, which could heat the cell to 34 °C (neglect of heat loss). This study simulates the failure process of the LIB in the operational state, which is expected to help the safety application of LIB and improve the reliability of the battery management system.

Download Full-text

Development of Life-cycle Detection and Extending Function for Reusing Automotive Lithium-ion Battery – Verified in 52V LiMnNiCoO2 Platform

10.21203/rs.3.rs-20563/v1 ◽

2020 ◽

Author(s):

Wu-Yang Sean ◽

Ana Pacheco

Keyword(s):

Life Cycle ◽

Lithium Ion Battery ◽

Management System ◽

Open Circuit Voltage ◽

Lithium Ion ◽

Open Circuit ◽

Battery Pack ◽

Battery Management System ◽

Battery Management ◽

Cycle Detection

Abstract For reusing automotive lithium-ion battery, an in-house battery management system is developed. To overcome the issues of life cycle and capacity of reused battery, an online function of estimating battery’s internal resistance and open-circuit voltage based on adaptive control theory are applied for monitoring life cycle and remained capacity of battery pack simultaneously. Furthermore, ultracapacitor is integrated in management system for sharing peak current to prolong life span of reused battery pack. The discharging ratio of ultracapacitor is adjusted manually under Pulse-Width-Modulation signal in battery management system. In case study in 52V LiMnNiCoO2 platform, results of estimated open-circuit voltage and internal resistances converge into stable values within 600(s). These two parameters provide precise estimation for electrical capacity and life cycle. It also shows constrained voltage drop both in the cases of 25% to 75% of ultracapacitors discharging ratio compared with single battery. Consequently, the Life-cycle detection and extending functions integrated in battery management system as a total solution for reused battery are established and verified.

Download Full-text

An Improved Test Method of LiFePO4/Graphene Hybrid Cathode Lithium-Ion Battery and the State of Charge Estimation

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4046930 ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Meiying Li ◽

Zhiping Guo ◽

Yuan Li ◽

Wenliang Wu

Keyword(s):

Lithium Ion Battery ◽

Equivalent Circuit Model ◽

Lithium Ion ◽

Open Circuit ◽

The State ◽

State Of Charge ◽

Least Square ◽

Test Method ◽

Battery Management System ◽

Battery Management

Abstract The state of charge (SoC) of the battery is a typical characterization of the operating state of the battery and criterion for the battery management system (BMS) control strategy, which must be evaluated precisely. The establishment of an accurate algorithm of SoC estimation is of great significance for BMS, which can help the driver judge the endurance mileage of electric vehicle (EV) correctly. In this paper, a second-order resistor-capacity (RC) equivalent circuit model is selected to characterize the electrical characteristics based on the electrochemical model of the LiFePO4/graphene (LFP/G) hybrid cathode lithium-ion battery. Moreover, seven open circuit voltage (OCV) models are compared and the best one of them is used to simulate the dynamic characteristics of the battery. It is worth mentioning that an improved test method is proposed, which is combined with least square for parameters identification. In addition, the extended Kalman filter (EKF) algorithm is selected to estimate the SoC during the charging and discharging processes. The simulation results show that the EKF algorithm has the higher accuracy and rapidity than the KF algorithm.

Download Full-text

Effects of electrode pattern on thermal runaway of lithium-ion battery

International Journal of Damage Mechanics ◽

10.1177/1056789516660176 ◽

2016 ◽

Vol 27 (1) ◽

pp. 74-81 ◽

Cited By ~ 2

Author(s):

Meng Wang ◽

Anh V Le ◽

Daniel J Noelle ◽

Yang Shi ◽

Hyojung Yoon ◽

...

Keyword(s):

Energy Storage ◽

Temperature Profile ◽

Lithium Ion Battery ◽

Heat Generation ◽

Specific Energy ◽

Storage Systems ◽

Lithium Ion ◽

Thermal Runaway ◽

Cathode Layer ◽

High Specific Energy

In the current study, through a set of nail penetration and impact tests on modified lithium-ion battery coin half-cells, we examine the effects of electrode pattern on the heat generation behaviors associated with internal shorting. The results show that the temperature profile is quite insensitive to the openings in cathode layer, which may be attributed to the high specific energy as well as the secondary conductive paths. This finding will considerably influence the study in the area of thermal runaway mitigation of energy storage systems.

Download Full-text

An Open Circuit Voltage Model Fusion Method for State of Charge Estimation of Lithium-Ion Batteries

Energies ◽

10.3390/en14071797 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1797

Author(s):

Quanqing Yu ◽

Changjiang Wan ◽

Junfu Li ◽

Lixin E ◽

Xin Zhang ◽

...

Keyword(s):

Open Circuit Voltage ◽

Stress Test ◽

Lithium Ion ◽

Open Circuit ◽

State Of Charge ◽

Battery Management System ◽

Fusion Method ◽

Battery Management ◽

Model Fusion ◽

Cubature Kalman Filter

The mapping between open circuit voltage (OCV) and state of charge (SOC) is critical to the lithium-ion battery management system (BMS) for electric vehicles. In order to solve the poor accuracy in the local SOC range of most OCV models, an OCV model fusion method for SOC estimation is proposed. According to the characteristics of the experimental OCV–SOC curve, the method divides SOC interval (0, 100%) into several sub-intervals, and respectively fits the OCV curve segments in each sub-interval to obtain a corresponding number of OCV sub-models with local high precision. After that, the OCV sub-models are fused through the continuous weight function to obtain fusional OCV model. Regarding the OCV curve obtained from low-current OCV test as the criterion, the fusional OCV models of LiNiMnCoO2 (NMC) and LiFePO4 (LFP) are compared separately with the conventional OCV models. The comparison shows great fitting accuracy of the fusional OCV model. Furthermore, the adaptive cubature Kalman filter (ACKF) is utilized to estimate SOC and capacity under a dynamic stress test (DST) at different temperatures. The experimental results show that the fusional OCV model can effectively track the performance of the OCV–SOC curve model.

Download Full-text

Thermal Simulation Analysis of a Lithium-Ion Battery

Advances in Theoretical & Computational Physics ◽

10.33140/atcp.04.01.15 ◽

2021 ◽

Vol 4 (1) ◽

Keyword(s):

Lithium Ion Battery ◽

Electric Vehicles ◽

Heat Generation ◽

Lithium Ion ◽

High Energy ◽

Thermal Runaway ◽

Transport Processes ◽

High Energy Density ◽

Battery Cell ◽

Discharge Rates

Lithium – Ion batteries are now extensively used in electric vehicles (EV) as well as in renewable power generation applications for both on-grid and off grid storage. Some of the major challenges with batteries for electric vehicles are the requirement of high energy density, compatibility with high charge and discharge rates while maintaining high performance, and prevention of any thermal runaway conditions. The objective of this research is to develop a computer simulation model for coupled electrochemical and thermal analysis and characterization of a lithium-ion battery performance subject to a range of charge and discharge loading, and thermal environmental conditions. The electrochemical model includes species and charge transport through the liquid and solid phases of electrode and electrolyte layers along with electrode kinetics. The thermal model includes several heat generation components such as reversible, irreversible and ohmic heating, and heat dissipation through layers of battery cell. Simulation is carried out to evaluate the electrochemical and thermal behavior with varying discharge rates. Results demonstrated a strong variation in the activation and ohmic polarization losses as well as in higher heat generation rates. Results show variation of different modes and order of cell heat generation rates that results in a higher rate of cell temperature rise as battery cell is subjected to higher discharge rates. The model developed will help in gaining a comprehensive insights of the complex transport processes in a cell and can form a platform for evaluating number new candidates for battery chemistry for enhanced battery performance and address safety issues associated with thermal runaway.

Download Full-text

(Invited) The Role of Internal Short Circuit during the Thermal-Induced Thermal Runaway Process of Lithium-Ion Battery

ECS Meeting Abstracts ◽

10.1149/ma2019-01/6/582 ◽

2019 ◽

Keyword(s):

Lithium Ion Battery ◽

Short Circuit ◽

Lithium Ion ◽

Thermal Runaway ◽

Internal Short Circuit ◽

Runaway Process

Download Full-text

Theoretical and experimental analysis of the lithium-ion battery thermal runaway process based on the internal combustion engine combustion theory

Energy Conversion and Management ◽

10.1016/j.enconman.2019.02.008 ◽

2019 ◽

Vol 185 ◽

pp. 211-222 ◽

Cited By ~ 4

Author(s):

Weifeng Li ◽

Hewu Wang ◽

Minggao Ouyang ◽

Chengshan Xu ◽

Languang Lu ◽

...

Keyword(s):

Internal Combustion Engine ◽

Lithium Ion Battery ◽

Experimental Analysis ◽

Combustion Engine ◽

Lithium Ion ◽

Internal Combustion ◽

Thermal Runaway ◽

Combustion Theory ◽

Engine Combustion ◽

Runaway Process

Download Full-text

Impact of Charging and Charging Rate on Thermal Runaway Behaviors of Lithium-Ion Cells

Journal of The Electrochemical Society ◽

10.1149/1945-7111/ac3c20 ◽

2021 ◽

Author(s):

Dongxu Ouyang ◽

Jingwen Weng ◽

Mingyi Chen ◽

Jian Wang

Keyword(s):

Lithium Ion ◽

Thermal Runaway ◽

Lithium Ion Cells ◽

Charging Rate ◽

Internal Morphology ◽

Cell Stability ◽

Initial States ◽

Micro Features ◽

The Impact ◽

Runaway Process

Abstract The present work carries out a series of thermal runaway experiments to explore the impact of charging and charging rate on the thermal runaway behaviors of lithium-ion cells, in which five charging rates (0C, 0.5C, 1C, 2C and 4C) and three initial states of charge (SOC), i.e. 25%, 50% and 75% are included. The thermal runaway process of 18650 lithium-ion cells induced by over-heating usually consists of seven stages, and is accompanied with high-temperature, fire and toxicity risks. The internal morphology of cells and the micro features of cell materials are seriously damaged after thermal runaway. Charging aggravates the thermal runaway behavior of cells, which is further exhibited as the earlier occurrence of safety vent opening, gas releasing and thermal runaway. Moreover, the severity deteriorates as the charging rate increases (the larger the charging rate, the earlier and more severe the thermal runway), which may be ascribed to the growth of cell SOC and the decline of cell stability under charging. This phenomenon is especially apparent for the cell with a high initial SOC where a more dramatic-rising α (the advancement ratio of critical times for thermal runaway due to charging) is observed.

Download Full-text

Development of Enhancing Battery Management for Reusing Automotive Lithium-Ion Battery

Energies ◽

10.3390/en13133306 ◽

2020 ◽

Vol 13 (13) ◽

pp. 3306 ◽

Cited By ~ 1

Author(s):

Wen-Poo Yuan ◽

Se-Min Jeong ◽

Wu-Yang Sean ◽

Yi-Hsien Chiang

Keyword(s):

Adaptive Control ◽

Lithium Ion Battery ◽

Lithium Ion ◽

Open Circuit ◽

Life Extension ◽

Duty Ratio ◽

Battery Management System ◽

Battery Management ◽

Control Approach ◽

Two Parameters

In this study, a battery management system (BMS) is developed for reused lithium-ion battery (RLIB). Additional enhancing functions of battery management are established, i.e., estimation of life-sensitized parameters and life extension. Life-sensitizing parameters mainly include open-circuit voltage (OCV) and internal resistances (IRs). They are sensitized parameters individually relative to state of charge (SOC) and state of health (SOH). For estimating these two parameters, an adaptive control scheme is implemented in BMS. This online adaptive control approach has been extensively applied to nonlinear systems with uncertainties. In two experiments, OCV and IRs of reused battery packs are accurately extracted from working voltage and discharge current. An offline numerical model using a schematic method is applied to verify the applicability and efficiency of this proposed online scheme. Furthermore, a solution of actively extending life by using an ultracapacitor to share peak power of RLIB through adjusting duty ratio is also proposed. It is shown that this enhancing battery management for RLIB can properly estimate OCV and IRs, and actively extend the life of the RLIB in two experiments.

Download Full-text