Understanding the Thermal Runaway of Ni-Rich Lithium-Ion Batteries

Abstract

The main safety issue pertaining to operating lithium-ion batteries (LIBs) relates to their sensitivity to thermal runaway. This complex multiphysics phenomenon was observed in two commercial 18650 Ni-rich LIBs, namely a Panasonic NCR GA and a LG HG2, which were based on L i ( N i 0.8 C o 0.15 A l 0.05 ) O 2 (NCA) and L i ( N i 0.8 M n 0.1 C o 0.1 ) O 2 (NMC811), respectively, for positive electrodes, in combination with graphite-SiOx composite negative electrodes. At pristine state, the batteries were charged to different levels of state of charge (SOC) (100% and 50%) and were investigated through thermal abuse tests in quasi-adiabatic conditions of accelerating rate calorimetry (ARC). The results confirmed the proposed complete thermal runaway of exothermic chain reactions. The different factors impacting the thermal runaway kinetics were also studied by considering the intertwined impacts of SOC and the related properties of these highly reactive Ni-rich technologies. All tested cells started their accelerated thermal runaway stage at the same self-heating temperature rate of ~48 °C/min. Regardless of technology, cells at reduced SOC are less reactive. Regardless of SOC levels, the Panasonic NCR GA battery technology had a wider safe region than that of the LG HG2 battery. This technology also delayed the hard internal short circuit and shifted the final venting to a higher temperature. However, above this critical temperature, it exhibited the most severe irreversible self-heating stage, with the highest self-heating temperature rate over the longest duration.

Ni‐Rich/Co‐Poor Layered Cathode for Automotive Li‐Ion Batteries: Promises and Challenges

“…Unfortunately, battery safety is also increasingly concerned owing to some drawbacks of Ni‐rich NCM. With the continuous increase of Ni content in NCM cathode, the consequently structural and interfacial instability, and low thermostability of Ni‐rich NCM would cause material degradation, serious side reaction, electrolyte decomposition, cell swelling, and finally trigger the whole cell thermal runaway, thus limiting the widespread application of Ni‐rich NMC 52. In this section, we mainly focus on safety issues of LIBs caused by Ni‐rich cathode at the abused conditions including overcharged state, thermal stability, thermal runaway, oxygen release, and so on, which is different with Part 4 (mainly focuses on cycling stability at the normal working state and calendar lifetime at the rest state).…”

“…Although some reviews have well summarized existing issues, material modification, and potential applications of Ni‐rich layered cathode materials,2,4,6,12,30,31,50,51,52 most reviews mainly focus on one aspect or two aspects (energy density, cycling lifetime, etc.) of the Ni‐rich NCM.…”

Future Material Developments for Electric Vehicle Battery Cells Answering Growing Demands from an End-User Perspective

“…Even blended in small fraction with graphite, this last parameter complicates the widespread implementation of the material in high concentrations for commercial LIBs [24,41,86]. However, it has been confirmed to be an anode component in Tesla's batteries [76,89].…”

Recent Progress on High‐Performance Cathode Materials for Zinc‐Ion Batteries

“…[1][2][3][4][5] However, LIBs display inherent safety and environmental issues, such as thermal runaway and toxic runoff from landfill disposal. [6][7][8] In addition, increasing prices and supply deficits for raw metals (Li, Co, Ni, etc.) are major concerns for the long-term outlook of LIBs. [9][10][11][12] Driven by these limitations and uncertainties pertaining to LIB technologies, there has been increasing interest in investigating alternative systems based on other chemistries.…”

“…[ 1–5 ] However, LIBs display inherent safety and environmental issues, such as thermal runaway and toxic runoff from landfill disposal. [ 6–8 ] In addition, increasing prices and supply deficits for raw metals (Li, Co, Ni, etc.) are major concerns for the long‐term outlook of LIBs.…”