Multi-perspective investigation on thermal safety of lithium iron phosphate batteries: From materials to cells

Thermal safety optimization in 628 Ah LiFePO4 batteries: Experimental and modeling study on thermal runaway propagation inhibition via size effects and internal barrier design

Dynamic thermal safety of Tesla-like lithium-ion battery packs: a transient analysis of cooling failures and overheating in electric vehicles

Thermal safety evolution of lithium-ion batteries under high-temperature float charge: implications of swelling and aging

This study investigated the implementation of a Battery Management System (BMS) as a protective and performance-enhancing component in a small-scale hybrid solar power plant storage system rated at 10 × 100 Wp. Battery degradation, voltage imbalance, and excessive discharge currents are persistent challenges in off-grid and hybrid photovoltaic systems, particularly in rural electrification applications. The purpose of this research was to evaluate the effectiveness of an active cell balancing–based BMS in improving battery voltage stability, regulating discharge current, and extending battery life cycles.The research employed an experimental method by comparing system performance before and after BMS installation under identical charging and discharging conditions. Experimental results showed that prior to BMS installation, charging voltages among four VRLA batteries were unbalanced, ranging from 13.70 V to 13.80 V, and discharge currents reached up to 50.3 A. After BMS implementation, charging voltages became uniform at approximately 13.44 V, while discharge currents were limited to a maximum of 29.9 A. Furthermore, the SOC threshold was regulated from 100% to 90%, and discharge duration increased from 1.5 hours to 2 hours. Based on battery datasheet analysis, the estimated battery life cycle increased from a maximum of 372 cycles to 572 cycles. These findings indicate that the integration of a BMS with active cell balancing significantly enhances operational stability, thermal safety, and battery longevity. The results imply that BMS adoption is essential for improving reliability and sustainability of small-scale hybrid solar energy systems.

Radiofrequency (RF) exposure has been extensively studied for potential health risks. Unlike ionizing radiation, RF fields primarily cause thermal health effects, the only established mechanism of biological harm. Regulatory bodies, including the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Institute of Electrical and Electronics Engineers (IEEE), set limits to prevent excessive heating. This review examines the relationship between RF exposure, heat generation, and physiological responses, with relevance to civilian and military safety. A narrative review of peer-reviewed literature, regulatory reports, and experimental studies was conducted using PubMed, IEEE Xplore, Google Scholar and Scopus. Emphasis was placed on Specific Absorption Rate (SAR) and Cumulative Equivalent Minutes at 43 °C (CEM43). Studies on thermal effects and exposure scenarios were prioritized; speculative non-thermal mechanisms were excluded. Thermal effects depend on frequency, tissue composition, and environmental conditions. Whole-body SAR limits (≤4 W/kg) generally prevent core temperature increases, but localized heating remains a concern. CEM43 provides a temperature-based metric but is difficult to apply in transient exposures. Penetration depth across NATO frequency bands shows variability because of differences in tissue models and measurement methods. This variability is clinically relevant, as localized heating of the skin, eye, or superficial nerves may occur even when whole-body exposure is within limits. Current guidelines prevent systemic overheating but may not fully address localized risks. Combining SAR and CEM43 with refined penetration depth data could improve risk assessment. Future work should refine dose-response thresholds and methods for detecting and modeling localized heating, especially under military conditions where thermoregulation may be impaired.

At present, composite phase change materials are widely studied for battery thermal management. However, to ensure the battery’s thermal safety, it is necessary not only to control the temperature during regular operation, but also to prevent sudden thermal runaway. This basic function depends on the flame-retardant properties of the composite phase change materials. In this study, a hexagonal double-layer hollow nanocage S2 with defect orientation was prepared and combined with carbon nanotubes (PNT) derived from polypyrrole (PPy) tubes to form a high adsorption mixture. Multifunctional composite phase change material PNT/S2@PEG/TEP was prepared by adsorbing and coating polyethylene glycol 8000 (PEG-8000) and triethyl phosphate (TEP) with microfibrillated cellulose nanofibers (CNF) as the skeleton. The characterization shows that its thermal conductivity is 0.65 W/m·K and its phase transition enthalpy is 146.1 J/g, demonstrating its excellent thermal regulation. Microcalorimetric testing (MCC) confirmed its flame-retardant ability, attributed to the strong adsorption of PNT/S2 on PEG-8000 and TEP, the improvement in PNT’s thermal conductivity, and the contribution of CNF to flexibility. This composite phase change material, with excellent comprehensive properties, has broad application prospects in thermal safety for electronic equipment, significantly expanding its practical scope.

To compare operative time and clinical outcomes between high-power (HP) and low-power (LP) thulium fibre laser (TFL) ureteroscopic (URS) lithotripsy for renal stones. Single-centre, randomised trial (1:1) at Haukeland University Hospital, Norway. Adults undergoing day-case URS for 8-25 mm renal stones were enrolled. A total of 150 cases were included. Patients were randomised to URS lithotripsy with TFL using HP (16-18 W, selected for thermal safety during sheathless URS) or LP (4-6 W). The primary endpoint was operative time. The secondary endpoints were stone-free rate (SFR) on 3-month non-contrast computed tomography (Grade A: no residuals; Grade B: ≤2 mm; Grade C: ≤4 mm; Grade D: >4 mm), laser metrics, performance measures, and complications according to the Clavien-Dindo Classification. Groups were compared using appropriate parametric and non-parametric tests (two-sided α = 0.05). A ureteric access sheath was not used in any case, reflecting routine practice at our centre. The operative time did not differ between arms: median (interquartile range) HP 48 (36-62) vs LP 54 (42-65) min (P = 0.12). HP used more energy (12 vs 7 kJ, P < 0.001) with shorter active laser time (13 vs 24 min, P < 0.001), but laser operating time was similar. SFRs favoured LP compared to HP: Grade A, 63% vs 44% (P = 0.02); Grade B, 77% vs 56% (P = 0.008). The Grade C SFR was similar between arms. LP was also associated with better surgeon-rated endoscopic visibility and fewer minor postoperative complications (11% vs 37%, P < 0.001). Major complications (Clavien-Dindo Grade ≥III) were uncommon and similar between arms. Using HP did not shorten the operative time. LP improved SFRs for Grade A/B and reduced minor postoperative morbidity, supporting LP as the default TFL strategy for sheathless URS lithotripsy.

The rise in thermal runaway events within electric vehicle (EV) battery systems requires anticipatory models to predict critical safety failures during operation. This investigation develops a multi-physics digital twin framework that links electrochemical, thermal, and structural domains to replicate the internal dynamics of lithium-ion packs in both normal and faulted modes. Coupled simulations distributed among MATLAB 2024a, Python 3.12-powered three-dimensional visualizers, and COMSOL 6.3-style multi-domain solvers supply refined spatial resolution of temperature, stress, and ion concentration profiles. While the digital twin architecture is designed to accommodate different battery chemistries and pack configurations, the numerical results reported in this study correspond specifically to a lithium NMC-based 4S3P cylindrical cell module. Quantitative benchmarks show that the digital twin identifies incipient thermal deviation with 97.4% classification accuracy (area under the curve, AUC = 0.98), anticipates failure onset within a temporal margin of ±6 s, and depicts spatial heat propagation through three-dimensional isothermal surface sweeps surpassing 120 °C. Mechanical models predict casing strain concentrations of 142 MPa, approaching polymer yield strength under stress load perturbations. A unified operator dashboard delivers diagnostic and prognostic feedback with feedback intervals under 1 s, state-of-health (SoH) variance quantified by a root-mean-square error of 0.027, and mission-critical alerts transmitting with a mean latency of 276.4 ms. Together, these results position digital twins as both diagnostic archives and predictive safety envelopes in the evolution of next-generation EV architectures.

Abstract The demand for safer, thermally stable lithium-ion batteries (LIBs) has driven the search for advanced electrolyte systems. This study introduces an electrolyte based on propylene glycol diacetate (PGDA) to improve thermal safety and stability. The optimized PGDA-based solvent mixture increases the flash point to 100 °C, which is approximately 63 K higher than that of the reference electrolyte LP40 (1 M LiPF6 in EC:DEC 1:1 wt). While the flash point is primarily determined by the solvent composition, the onset of exothermic reactions depends on the conducting salt. Replacing lithium hexafluorophosphate (LiPF6) with lithium bis(oxalato)borate (LiBOB) significantly improves thermal stability, cycling performance, and safety, as cells with LiBOB retain over 97% of their capacity after 100 cycles at 40 °C at C-rates up to 1C. Thermal abuse tests up to 300 °C exhibit no exothermic reactions, thereby preventing dangerous thermal runaways. These findings underscore the potential of PGDA-based electrolytes, especially when paired with LiBOB, for safer and more robust LIB applications.&amp;#xD;

Thermal Safety Driven Minimum Wall Thickness for Single-Layer Bio-Based Hot-Beverage Cups at 100 °C: Analytical Bound and Transient Verification

Non-thermal biological effects of radiofrequency electromagnetic radiation: Mechanistic insights into male reproductive vulnerability in the era of ubiquitous exposure.

Fabrication of multifunctional hydrophobic silica aerogels with superior thermal safety enabled by a dual flame-retardant strategy

A multifunctional ionic hydrogel facilitating enhanced thermal safety for lithium-ion battery via overheating cooling, intelligent warning, and thermal runaway blocking

Mechanistic Insights Into the Electrochemical and Thermal Safety Degradation of Lithium Titanate Batteries Under Constant Voltage Overcharge Conditions

Efficient design of proton exchange membrane fuel cells (PEMFCs) requires balancing high electrical output with thermal stability, yet the complex interactions among operating parameters make this a challenging task. Addressing this gap, this study develops an integrated predictive–optimization–decision framework that systematically models PEMFC performance, explores trade-offs, and guides application-specific design choices. The primary innovation lies in combining multi-layer perceptron neural networks (MLPNN) with metaheuristic optimization, particle swarm optimization (PSO), modified particle swarm optimization (MPSO), multi-objective Harris hawks optimization (MOHHO), and multi-objective PSO (MOPSO), followed by decision-making using the additive ratio assessment (ARAS) method. Predictive modeling results demonstrate variable-specific advantages of optimization strategies: PSO-MLPNN yielded superior accuracy for electrical power output prediction (MAPE = 0.233%), while MPSO-MLPNN achieved marginally better accuracy for cell temperature prediction (MAPE = 0.301%). Multi-objective optimization revealed the inherent trade-off between power and temperature, with MOHHO providing broader Pareto fronts and greater diversity than MOPSO. Optimal operating conditions (STAn ≈ 2.0–2.15, STCa ≈ 2.1–2.3, RHCa ≈ 60–66%, Tin ≈ 26 °C) enabled peak power outputs near 5300 mW while maintaining stable cell temperatures around 39.5 °C. Finally, ARAS-based decision analysis identified seven design scenarios. The scenario with balanced weights yielded a cell power output of 5205.9 mW, representing an increase of approximately 6.94% compared to the mean cell power of 4867.9 mW in the dataset. The corresponding cell temperature was 39.53 °C, which is about 20.3% lower than the mean cell temperature of 49.61 °C. These results demonstrate the proposed framework’s ability to provide flexible and application-specific design strategies, simultaneously enhancing electrical performance and maintaining thermal stability and safety.

The growing adoption of electric vehicles (EVs) and the increasing integration of variable renewable energy sources (RES), such as solar and wind, present significant challenges for grid stability, battery health, and energy management during fast charging. This study proposes a novel hybrid control strategy that combines offline-tuned Fuzzy Logic Control (FLC) with Model Predictive Control (MPC) to enhance the efficiency and reliability of EV fast charging in grid-connected, RES-driven environments. Unlike conventional approaches that rely solely on MPC or FLC, the proposed method leverages FLC’s adaptive decision-making to optimize key MPC parameters offline, thereby improving real-time responsiveness and control robustness. Once tuned, the MPC controller predicts grid states, renewable power fluctuations, and EV charging dynamics to optimize charging speed while maintaining thermal safety, reducing battery degradation, and minimizing grid stress. Simulation and experimental results under various operating conditions—including fluctuating renewable inputs, multiple EV charging demands, and dynamic grid behaviour, demonstrate that the proposed hybrid controller significantly outperforms traditional methods in terms of charging efficiency, power quality, battery protection, and renewable energy utilization. The findings also highlight the potential for extending this control framework to future vehicle-to-grid (V2G) applications, contributing to more resilient and sustainable smart grid operations.

Thermal damage during bone drilling remains a significant concern in orthopaedic and dental surgeries. Excessive heat generation at the bone–drill interface can result in thermal necrosis and compromise implant stability. While several strategies have been proposed to mitigate intraoperative thermal injury, however, quantitative evaluations of staged drilling techniques remain limited. This study investigates the efficacy of a two-stage drilling strategy in reducing heat generation during cortical bone drilling. The approach involves creating an initial (pre-drilled) hole, followed by final enlargement to the target diameter (pilot hole). A validated three-dimensional dynamic elastoplastic finite element (FE) model was developed to simulate the bone drilling process and compare the bone temperature of conventional single-stage versus two-stage drilling techniques. Thermal analyses were conducted incorporating variations in the pre-to-pilot hole diameter ratio, feed force, and drill rotational speed. Simulation results indicated that a diameter ratio of 0.78 reduced peak bone temperatures by up to 12 °C compared to single-stage drilling. Further reductions in thermal accumulation were observed with increased feed forces of 40 N and 60 N. Increasing drill rotational speed from 800 to 2000 rpm decreased peak cortical bone temperatures from 57 °C to 43 °C. These findings demonstrate that the two-stage drilling strategy may mitigate thermal bone damage. The two-stage approach provides a practical solution to enhance thermal safety during implant site preparation.

ABSTRACT Lithium‐ion batteries are the preeminent energy storage technology in consumer electronics, electric vehicles, and grid‐level applications. Nevertheless, they present significant safety hazards including thermal runaway that results in catastrophic failure due to the flammability of carbonate‐based electrolytes. The pursuit of enhanced energy density through nickel‐rich cathodes and lithium‐metal anodes further exacerbates these concerns. To address these challenges, this study reports a nanocomposite gel electrolyte (NGE) incorporating flame‐retardant Mg(OH) 2 (magnesium hydroxide, MH) nanoplatelets. NGEs using MH nanoplatelets provide robust mechanical properties (&gt;20 MPa storage modulus) with high room‐temperature ionic conductivity (≈1 mS cm −1 ), while remaining compatible with scalable slurry‐based fabrication. Additionally, MH nanoplatelets enhance thermal safety due to endothermic decomposition at elevated temperatures that mitigates thermal runway, release of water vapor as a combustion suppressant, and formation of MgO char that inhibits flame propagation and maintains electrode separation. Moreover, MH NGEs can be configured into bilayer electrolytes, expanding the electrochemical stability window for higher energy densities. Notably, an MH‐based bilayer gel electrolyte incorporating diglyme and succinonitrile layers significantly improves cycle life in LFP|Li and NCA|Li cells compared to either layer alone. These results highlight the potential of MH NGEs as safe and scalable electrolytes for next‐generation lithium energy storage technologies.

Thermal safety remains a critical factor for the widespread adoption of sodium-ion batteries as next-generation energy storage technology. Conventional organic interfaces with poor thermal stability fail to protect the sodiated hard carbon formed through multimodal sodium storage under various abuses, particularly the highly reactive sodium clusters formed by pore filling, thus introducing substantial potential safety risks. Herein, a dual-functional high-entropy solid electrolyte interphase featuring a disordered hybrid of inorganic components is constructed on hard carbon. The high-entropy inorganic interface contains multidimensional ion transport channels with low diffusion energy barriers to drive sodium-ion deep storage with more pore-filling pathways in hard carbon, largely increasing the sodium storage capacity. NaNi1/3Fe1/3Mn1/3O2/hard carbon coin cell demonstrates 80% capacity retention after 800 cycles at a cathode loading of 17 mg cm-2. The energy density of 146.2 Wh kg-1 is achieved for the 3.7 Ah 26700 cylindrical cell. Concurrently, the thermally stable inorganic-rich interface strongly hinders the heat production from electrode-electrolyte reactions, significantly enhancing thermal safety of sodium-ion batteries. The thermal runaway onset temperature of the fully charged pouch cell is increased from 52.4 to 161.9 °C, and the maximum temperature rise rate is decreased from 1628.5 °C min-1 to 17.4 °C min-1. This work provides new insights into modulating the sodium storage mechanism and enhancing the safety of sodium-ion batteries.