Tests were performed inside our fractional thermal runaway calorimeter to quantify the heat transferred and its distributions and those runs done at a synchrotron yielded fascinating very high-speed X-ray videography. These show tolerance to nail penetration and activation of defect internal shorts and when thermally forced into thermal runaway, the heat output is significantly reduced.

Internal short circuits and the resulting catastrophic battery failure is difficult to detect and can occur under normal working conditions. To enable future high-energy density batteries, particularly lithium metal, an inexpensive internal short protection scheme is required. Here, we selectively remove conductive carbon from the cathode surface, creating a gradient-conductivity electrode.

This presentation will focus on Solid Electrolyte (SE) cells and the Safety and Failure analysis considerations. The energy density of SE’s is the biggest draw since SEs are expected to satisfy energy and power requirements of electric vehicles and enabling electric aircraft. With increasing advancements in SE cells, it is important to have specialized abuse testing and failure analysis techniques that can determine performance and safety concerns.

This presentation shows the setup and results of three different thermal runaway triggers, different cell chemistries, and different aging paths of modern battery cells in a custom-made TR reactor. It focuses on the trigger overtemperature, overcharge, and nail penetration. The investigated cell types are state-of-the-art automotive cells. Different thermal runaway trigger methods, cell chemistries, and aging paths have an impact on the battery failing behavior. Results will be presented and discussed in the categories: thermal behavior, vent gas production, and vent gas composition. In the second part of the presentation, experimental results of the use of different gas sensors as early detectors of battery failures will be proposed.

In this talk, we will disseminate our recent results on cell variability during thermal runaway test., with statistical analysis. Thermal runaway suspension with health retention will also be discussed.

Layered lithium transition metal oxide are one of the most promising cathode materials for next-generation lithium-ion batteries due to their high specific capacity. However, they suffer from severe safety concerns due to their poor thermal stability. Herein, we have presented a comprehensive understanding of the failure mechanism and developed a series of approaches by tailoring the composition, structure and surface of layered cathodes to bypass the degradation pathway.

By combining mechanical abusive testing and physics-based models on commercialized cells with various state-of-health and state-of-charge, we discovered that the ISC triggering delays with the decay of SOH and soft ISC mode will be triggered more frequently, mainly due to the mechanical behaviors of the current collectors. The peak temperature during the subsequent TR also becomes milder for aged cells due to the reduced capacity and deterministic soft ISC process.

Battery safety fundamentally relies on the underlying electrochemical-chemical-thermal interactions, involving complex interfaces and degradation mechanisms. Dependent on the battery chemistry and reaction pathways, intrinsic factors including the stability of the electrode/electrolyte interfaces, interphase growth, morphological behavior, and oxygen release has a distinct effect on the thermal stability response. In this presentation, a mechanistic framework, synergistically integrating electrochemical analytics, calorimetry, and physics-based modeling to probe the critical role of degradation-safety interactions will be discussed.

A precise interpretation of Lithium-ion Battery (LIB) heat generation is indispensable for different applications including electric vehicles. The internal resistance of a lithium titanate oxide-based LIB was determined at different state of charge (SOC) levels and current rates to understand the relationship between internal resistance and heat generation. Random and different pulse discharge current step durations were applied to consider the effect of different SOC interval levels on the heat generation. The total generated heat was measured for different discharge rates and operating temp.

This presentation will cover the regulatory safety initiatives that are ongoing to develop a packaging standard for lithium batteries transported by aircraft and to regulate lithium batteries based on their inherent hazards including their ability to propagate from cell to cell and how violent they react when forced into thermal runaway. 

The presentation will start with a series of fire experiments using cylindrical and pouch Lithium-Ion Battery (LIB) cells. Venting gas compositions, venting rates, and fire behaviors will be compared in detail between different cell States of Charge (SOC). We will then present the concept and methodology to develop a physics-based numerical model for LIB fires using the data obtained in the experiments. Preliminary modeling results will also be shared.

This presentation will explore the fire department's response to battery-related incidents. A post-incident view of battery safety will be given.

With code requirements in NFPA 855 for explosion control, the mitigations for achieving this vary greatly in both complexity and reliability. We will discuss best practices emerging for deflagration prevention designs for BESS cabinets.

When abused, lithium-ion batteries can go into thermal runaway, leading to smoke, fire, and high temperatures. Once ignited, lithium-ion battery fires can be difficult to extinguish, and re-ignitions are frequently observed. In this talk, we will summarize the experiments conducted with three different fire suppressants (water, nitrogen gas, and potassium-based aerosol) and lithium-ion modules of two different chemistries.