The Hazards Analysis of Nickel-Rich Lithium-Ion Battery Thermal Runaway under Different States of Charge

Kun Jiang,Chenghui Zhang,Bin Duan,Pingwei Gu,Peng Huang,Ying Zhang

doi:10.3390/electronics10192376

Abstract

The lithium-ion battery industry has been developing rapidly, with energy density and capacity constantly improving. However, the ensuing safety accidents of lithium-ion power batteries have seriously threatened the personal safety of passengers. Therefore, more and more attention has been paid to the thermal safety research of lithium-ion batteries, such as thermal runaway (TR) mechanism analysis and prevention methods, etc. In this paper, the nickel-rich 18650 lithium-ion batteries with Li[Ni0.8Co0.1Mn0.1]O2 cathode in different states of charge (SOC) are taken to investigate the TR characteristics using an extended volume plus acceleration calorimeter (EV+-ARC). In order to evaluate the TR characteristics, some characteristic parameters such as battery voltage, surface temperature, temperature rise rate, etc. are selected from the experiment to analyze the influence of SOC on the critical state of TR. It can be seen from the experiment results that the maximum temperature of the battery surface decreases with the decrease of SOC, while the self-generated heat temperature and TR trigger temperature increases with the decrease of SOC.

Highlights

In recent years, with the continuous increase in the use of fossil fuels, the energy crisis and environmental pollution have become more and more serious
In order to evaluate the thermal runaway (TR) characteristics, some characteristic parameters such as battery voltage, surface temperature, temperature rise rate, etc. are selected from the experiment to analyze the influence of states of charge (SOC) on the critical state of TR
It can be seen from the curves with 100% SOC in Figure 6a, that the TR processes could be divided into four stages with three critical temperatures

Summary

Introduction

With the continuous increase in the use of fossil fuels, the energy crisis and environmental pollution have become more and more serious. The development of cathode materials with high specific capacity is one of the most effective ways to improve the energy density of lithium-ion batteries. When the generated gas and heat cannot be fully discharged or once a battery with a higher energy density enters the thermal runaway (TR), it will inevitably cause more serious damage such as fire and explosion [10,11,12,13] It is of great significance for the progress of EVs to carry out research on the TR harms of high energy density lithium-ion batteries. The nickel-rich 18650 lithium-ion batteries with the Li[Ni0.8Co0.1Mn0.1]O2 cathode in different SOC conditions are taken to investigate the TR characteristics using the extended volume plus acceleration calorimeter (EV+-ARC). All the experiments are carried out in the thermostat at 25 ◦C

Thermal Runaway Experiment

Temperature and Voltage Change in TR Experiments

Influence of Different SOC Conditions on the Harm of Battery Thermal Runaway

Energy Calculation and Conversion

Conclusions