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Predicting thermal safety events of lithium-ion (Li-ion) batteries is significant in optimizing electrochemical systems with high thermal tolerance. The safety performances of Li-ion batteries are dictated by the thermal stability of their component materials both individually and collectively due to intricate exothermic reactions. Although the heat release of individual battery material has been thoroughly investigated, the safety hazards of inter-electrode chemical crosstalk under thermal abuse scenarios remain elusive and thus need a fundamental understanding. This study carries out a comprehensive thermal analysis of various material samples harvested from a commercial Li-ion cell using differential scanning calorimetry (DSC), complemented with full-cell accelerating rate calorimetry (ARC) and computational modeling. Reaction kinetics of electrolyte, wet cathode, wet anode and DSC-full cell samples imitating cell layered architectures are delineated to reveal substantial thermal interactions between electrodes. High-resolution kinetic parameters of reaction mechanisms are estimated using a synergy of Kissinger's method and mechanism-driven non-linear optimization strategies. A thermal abuse model is built based on the extracted kinetic parameters to simulate the cell-level thermal runaway phenomenon and compared with experimental observations, indicating how interlayer crosstalk effects significantly impact the thermal safety characteristics of Li-ion cell chemistries.

Energy storage using lithium-ion cells dominates consumer electronics and is rapidly becoming predominant in electric vehicles and grid-scale energy storage, but the high energy densities attained lead to the potential for release of this stored chemical energy. This article introduces some of the paths by which this energy might be unintentionally released, relating cell material properties to the physical processes associated with this potential release. The selected paths focus on the anode–electrolyte and cathode–electrolyte interactions that are of typical concern for current and near-future systems. Relevant material processes include bulk phase transformations, bulk diffusion, surface reactions, transport limitations across insulating passivation layers, and the potential for more complex material structures to enhance safety. We also discuss the development, parameterization, and application of predictive models for this energy release and give examples of the application of these models to gain further insight into the development of safer energy storage systems.

While lithium-ion batteries are continually increasing in energy and power density, thermal safety still remains a significant concern. In some thermal abuse scenarios, thermal runaway can be triggered by the exothermic reactions from inter-electrode chemical crosstalk between the cathode and the anode without an internal short circuit. Under these circumstances, the thermal runaway temperature is lower than the separator's thermal shrinkage temperature, implying that the cell's catastrophic thermal runaway occurs without a large-scale short circuit produced by separator failure. These cell failures must be managed such that the neighboring cells in a battery module are not affected, a phenomenon known as thermal runaway propagation. In the present work, we employed a high-resolution cell-level thermal runaway model constructed from the accelerating rate calorimetry data of a commercial Li-ion cell to characterize the cell-to-cell thermal runaway propagation behavior for a basic square arrangement of lithium-ion battery module connected by tabs. We determined safe practices under the effects of different ambient conditions, inter-cell spacing, trigger cell location, and external heating power. Additionally, we have identified the critical pathways for the thermal runaway propagation in the battery module and quantified their statistical distribution in terms of the thermal runaway propagation speed, heat release from exothermic reactions, and heat dissipation to the surroundings. The findings from the study are believed to be of immediate relevance for the safer design of lithium-ion battery packs.

Adverse lithium plating is a significant side reaction during the fast charging of lithium-ion (Li-ion) batteries when the Li-ion flux exceeds the intercalation or diffusion limits of graphite electrodes. Accurate quantification of lithium plating has always been a tough challenge given the severe defects of online detection methods such as coulombic efficiency and voltage relaxation plateau, making the mathematical correlation between cell-level thermal safety hazards and quantitative lithium plating events still a bottleneck problem. In this study, we apply a three-electrode (3E) Li-ion cell configuration and the accelerating rate calorimeter (ARC) to comprehensively investigate the interplay of unfavorable lithium plating on thermal runaway characteristics of Li-ion batteries. Lithium plating is introduced by cycling 3E Li-ion cells at low temperatures and quantified by analyzing potential-based plating energy, coulombic inefficiency, internal resistance, and voltage relaxation plateau. Surface microscopic characterization is carried out on graphite electrodes to reveal the morphologies and chemical states of lithium deposition. ARC experiments are implemented at full-cell and partial-cell scales to fundamentally understand the effects and contributions of thermally unstable lithium plating to the overall safety performance of Li-ion cell chemistries.

Annexin A1 is a Ca2+-dependent phospholipid binding protein involved in a variety of pathophysiological processes. Accumulated evidence has indicated that Annexin A1 has important functions in cell proliferation, apoptosis, differentiation, metastasis, and inflammatory response. Moreover, the abnormal expression of Annexin A1 is closely related to the occurrence and development of tumors. In this review article, we focus on the structure and function of Annexin A1 protein, especially the recent evidence of Annexin A1 in the pathophysiological role of inflammatory and cancer. This summary will be very important for further investigation of the pathophysiological role of Annexin A1 and for the development of novel therapeutics of inflammatory and cancer based on targeting Annexin A1 protein.

The thermal instability of polymer separators severely threatens the safety characteristics of lithium-ion (Li-ion) batteries. Separators will melt, shrink, vaporize, and collapse under high temperatures, leading to internal short circuits and thermal runaway catastrophes of the cell. Therefore, the amelioration of battery safety challenges benefits from a fundamental understanding of separator behaviors under thermally abusive scenarios. This work investigates the role of separator thermal stability in modulating Li-ion cell safety performance. Three types of separators made of commercially available cellulose, trilayer polypropylene/polyethylene/polypropylene, standard polypropylene, and an in-house modified graphene-polydopamine coated separator are fabricated in custom single layer pouch cells and subjected to accelerating rate calorimeter (ARC) tests to investigate dynamic thermo-electrochemical interactions. The safety hazards of 18650 cylindrical cells assembled with different types of separators are predicted using a verified ARC computational model to compare the effects of separator heat resistance on cell-level thermal runaway risks. This study reveals the thermally robust mechanisms of diverse separator microstructures, indicating how the in-house modified graphene-polydopamine coated separator significantly enhances the safety limits of Li-ion batteries.

A pouch cell method for retesting double-sided electrodes harvested from commercial lithium-ion batteries in a 3-electrode cell arrangement has been developed. By relying on pressure from restraint plates to make tab electrical connections, this method (1) requires no welding, (2) does not require a dry room, (3) does not require precision sealing equipment inside of an inert-gas glove box, and (4) does not require removal of composite material off of one side of the electrode which may compromise the composite to be tested on the other side. Lithium chips pressed onto copper mesh serve as the reference and counter electrodes and the electrolyte used was 1.0 M LiPF6 1:1 ethylene carbonate (EC):Diethyl carbonate (DEC) v/v. Electrochemical cycling of electrodes from a commercial 3.6 Ah 18650 lithium-ion cell demonstrated cell function and showed stable capacity and potential charge/discharge profiles after two cycles for the cathode and four cycles for the anode. The areal capacity of the anode and cathode was determined to be 5.50 ± 0.31 and 5.50 ± 0.30 mAh/cm2, respectively, based on a potential range of 0.005–1.5 V versus Li/Li+ for the anode and 3.0–4.25 V versus Li/Li+ for the cathode. High frequency, 500 kHz impedance measurements of the anode and cathode cells shows a real impedance of 1.55 Ohms and 2.17 Ohms, respectively, which is similar to prior studies on pouch cells with continuous tabs of similar capacity.

There are many welded thin-walled square tube structures in ship structures. At present, researchers are mainly involved in axial compressive ultimate strength of square tubes with large aspect ratios. However, the study of square tubes with small aspect ratios on ultimate strength capacity have seldom been conducted. In order to study the ultimate strength capacity of thin-walled square tubes with small aspect ratio under axial compression, three welded thin-walled square tubes with different slenderness ratios were manufactured and studied in this paper. The ultimate strength of those models under axial compression were obtained experimentally. The experimental results were compared with numerical results performed by ABAQUS. The influence of slenderness ratios on the axial compressive ultimate strength of thin-walled square tubes is analyzed, and a feasible modelling of finite element method is proposed.

Annexin A1 is a Ca2+-dependent phospholipid binding protein involved in a variety of pathophysiological processes. Accumulated evidence has indicated that Annexin A1 has important functions in cell proliferation, apoptosis, differentiation, metastasis, and inflammatory response. Moreover, the abnormal expression of Annexin A1 is closely related to the occurrence and development of tumors. In this review article, we focus on the structure and function of Annexin A1 protein, especially the recent evidence of Annexin A1 in the pathophysiological role of inflammatory and cancer. This summary will be very important for further investigation of the pathophysiological role of Annexin A1 and for the development of novel therapeutics of inflammatory and cancer based on targeting Annexin A1 protein.

Thermal safety hazards are a bottleneck problem that constrains the development of lithium-ion batteries with high energy density. Although the internal short circuit (ISC) caused by separator rupture has been identified as a primary driver of catastrophic failure, the effects of separator architecture and high-temperature robustness on thermal runaway behaviors still need fundamental understanding. This study investigates custom-built pouch cells assembled with a wide range of separators to understand the impact of separators on cell-level thermal stability and resistance to catastrophic ISC. Carefully designed thermal abuse tests reveal how the separator shrinkage, melting, and collapse correlate with micro and massive ISC to drive the unstoppable thermal runaway. Cells are subjected to extreme operating conditions to facilitate quantification of the role of separator characteristics on the thermal runaway signature. The implications of separator distinctions on modulating chemical crosstalk between anode and cathode are explored to determine the dominant mechanism that triggers the onset of thermal runaway, with mitigation strategies being proposed from a new perspective.

The thermal safety of lithium-ion batteries poses a serious concern towards using high power and energy-dense batteries for electric vehicles. The lithium-ion battery performance in a pouch cell format is greatly influenced by heterogeneity at different scales that translate to localized over-potentials, heat generation, plating severity, and mechanical stress. Such localized thermo-electrochemical-mechanics interactions can arise due to microstructural variability at mesoscale and cell architecture-induced heterogeneity (tab design) at a macro-scale. We use a microstructure resolved macro-scale (pouch cell) model to develop a fundamental understanding of the influence of heterogeneity on cell performance in terms of localized temperature rise, plating severity, and accelerated degradation under operational extremes. Finally, the effect of thermo-electrochemical interactions on localized lithium deposition is coupled to a thermal abuse model. The modeling capability elucidates the impact of plating heterogeneity on thermal runaway dynamics within a pouch cell operated under thermal abuse conditions.

Although lithium-ion batteries are driving the prosperity of the rechargeable world, safety catastrophes under extreme conditions are still one of the main challenges. Overdischarge is a common electrical abuse that may arise in a Li-ion battery pack when an extreme cell voltage imbalance occurs. The electrode cross-talk under an overdischarge scenario is still an open question. To fill this gap, Li-ion pouch cells with reference electrode configurations are fabricated to decouple anode and cathode characteristics from full cell performances. Electrode potentials vs. Li/Li+ at discharge, relaxation and charge phases are measured and interpreted. State of health deterioration is tracked through temperature, volume and impedance monitoring. Surface microscopic characterizations are implemented to explore morphologies and chemical states of electrodeposition. Electrolyte transformation and gas generation are determined using the gas chromatography-mass spectroscopy technique. This study reveals an implicit cathode-centric degradation mechanism in overdischarge extremes, providing a new perspective on overdischarge mitigation strategies.