Stresses resulting from electrode chemomechanics are strongly coupled to solid electrolyte-electrode interface failures. Such failures are significant barriers to realization of solid-state batteries (SSBs) and may result in significant safety issues including lithium dendrites. Using understandings of SSBs chemomechanical effects, we form long cycle-life SSBs with practical areal capacity (5 mAh/cm2) operating under low stack pressures at room temperature. Our findings highlight the importance of controlling cathode chemomechanics in SSBs.

Lithium metal batteries offer high-energy density but face safety challenges from dendrite growth, especially at scale. Solid-state batteries were introduced to block dendrites but often fail due to defects. Self-healing separators address this by autonomously repairing defects, eliminating dendrite pathways. This talk presents the operating principles of these separators and recent advancements in scaling the technology for full-scale automotive deployment.

This talk examines safety considerations in solid-state batteries using a bottom-up approach. By analyzing material behavior and interface interactions, we identify potential failure mechanisms and highlight emerging insights that challenge assumptions about the inherent safety of solid-state systems.

Battery safety depends on a myriad of parameters, including the active and passive materials, the electrode architecture, as well as the cell design. This study is focused on systems that use air-stable zinc anodes, mildly acidic aqueous electrolyte, and metal oxide cathode materials. These systems may serve as promising alternatives to non-aqueous batteries such as lithium-ion.

This talk presents some recent developments in zinc rechargeable batteries using the novel technology "Segmentation of Electrolyte (SoE)", to control the reaction distribution on the zinc anode in laminated cells. It also covers operando observations of zinc deposition and dissolution in zinc flow cells, revealing the correlation between the operating conditions and the rechargeability.

Lithium-ion batteries are widely used across various industries, ranging from portable consumer electronics to automotive, aerospace, and defense applications. When lithium-ion batteries are subjected to certain off-nominal conditions, they may experience thermal runaway which may result in the significant release of gaseous and particulate emissions and be accompanied by smoke/fire, posing a severe risk to human health and the environment. This presentation will feature a discussion of controlled laboratory experiments aimed at characterizing emissions observed during failure of li-ion batteries. Experiments included tests at different states-of-charge, and different battery cathode chemistries. Results from this research provide critical insight into thermal runaway hazards, which will help inform emergency response, as well as, in the development of mitigation and control strategies.

This presentation will describe failure physics and dangers after cell venting, as well as passive and active countermeasures that can be deployed based on fast detection system that is generally agnostic to electrochemistry, cell design, and system configuration.

As EVs become more mainstream, safety concerns are paramount for OEMs, consumers, and regulators. Owing to thermal runaway risks in an EV crash incident, it is important to know the mechanical deformation that triggers internal shorting. Understanding mechanical design limits helps design crashworthy vehicles while balancing the need for lightweighting. In this presentation, a cell-to-vehicle crash simulation workflow will be discussed. LS-DYNA models were calibrated and subsequently validated against cell experimental data. Multiphysics models that captured a battery cell’s electrical, mechanical, and thermal behaviors were then used in simulation of full electric vehicle crash.

This presentation focuses on the findings of WMG’s published work for the UK government Office for Product Safety and Standards (OPSS), on battery fire safety for PLEVs. Real-world statistics highlighted the severity of fires when batteries are charged or stored indoors. A review of UK legislation and international standards revealed inconsistencies and shortcomings that may contribute to the likelihood and severity of fires. Inspection and testing of available e bike, e-scooter and conversion kit batteries showed how reasonably foreseeable misuse can result in severe fire hazards in products with inadequate protection systems or inferior manufacturing quality. WMG made over 70 suggestions, for various stakeholders, aimed at reducing the frequency and severity of these fires.

Natrion’s Active Separator is a solid-state electrolyte separator that is a drop-in replacement to standard polyolefin lithium battery separators. Active Separator enables reduced liquid electrolyte use inside cells to minimize energy release in the event of a cell failure. Cells assembled with Active Separator demonstrate superior performance in nail penetration and calorimetry testing. When thermally degraded, Active Separator assists in neutralizing oxygen and hydrogen evolution during cell failure. Active Separator also enables Li-metal cells, in which its high mechanical strength and stability offer dendrite resilience and retention of cell integrity even at temperatures exceeding the melting point of lithium.

Layered LiMO2, Li, and Mn-rich oxides, and Co-free, Li-excess spinel (LxS) cathode, are popular cathode materials currently considered for automotive applications. The performance of these materials depends on the composition, structure, local environment, and synthesis conditions. Herein, I will present few examples using atomistic modeling to provide few insights into the lithiation and layering mechanisms of NMC materials, and oxygen redox activity in LxS.

Sodium-ion batteries are gaining commercial traction as a possible alternative to lithium-ion batteries in some applications such as BESS and EV. Some of the cell chemistries claim safety advantages over lithium-ion; however, understanding and evaluating these claims will be integral for the continuing development and maturity of this technology. This presentation will review findings from testing and analysis at Exponent, as well as public literature detailing various safety trade-offs.

Handling and transporting aged or defective battery cells is a key challenge in establishing an efficient battery recycling infrastructure. An important prerequisite for such a system is the development of suitable methods for the pretreatment and deactivation of lithium-ion and lithium-metal batteries. Additionally, the extraction of lithium is getting more attention to achieve an overall better recycling efficiency. Here, we present some of our latest results on the topic.

Thermal Runaway (TR) of LiBs is the key to safety. It involves multi-scale phenomena ranging from internal physic-chemical mechanisms to battery components including safety features (CID, pressure disk, vent) and further to thermal propagation. At IFPEN, a Multiphysics Multiscale model is developed to be able to simulate the cell behavior under different initiation events (overheating, overcharging, short circuiting). The impacts of chemistry, SOC, and aging are studied.

Battery applications are increasing in number and complexity, calling for more robust tools for life predictions and health diagnostics. While we hope batteries “age gracefully," there is an abiding need to monitor battery health for signs of failure precursors such as lithium plating in Li-ion cells. This work showcases INL tools (measurements plus models) that determine metrics of lithium plating, and the consequences of aged electrolyte on battery performance. New pulse-based tools dissect the contributive resistive elements, allowing assessment of available power over broad conditions. Our approach gains knowledge on mechanisms that impact battery health/life, gaining insights on mitigation strategies.

Overdischarge accelerates battery degradation, with copper dissolution and deposition potentially causing internal shorts and catastrophic failure. To address this, we develop a reduced-order Thermal Tanks-in-Series (TTiS) model that efficiently predicts voltage-time profiles and capacity fade under varied overdischarge protocols. Extending this to battery modules, where series-parallel connections and voltage cutoffs at the module level can cause individual cell overdischarge, the model captures the effects of cell variability and module design. The scalable framework enables accurate, efficient simulation of capacity degradation in large-scale battery systems.