A Multiphysics Model Simulating the Electrochemical, Thermal, and Thermal Runaway Behaviors of Lithium Polymer Battery

Abstract

Lithium-ion batteries (LIBs) have circumvented the energy storage landscape for decades. However, safety concerns about liquid–electrolyte-based LIBs have challenged their mobilization. Lithium polymer (LiPo) batteries have gained rising interest due to their high thermal stability. Despite an array of commercially available LiPo batteries, limited studies have ventured into modeling. Numerical simulations allow low-cost optimization of existing battery designs through parameter analysis and material configuration, leading to safer and more energy-efficient batteries. This work examined the electrochemical, thermal, and thermal runaway behavior of a lithium cobalt oxide cathode, graphite anode, and poly(vinylidene fluoride-hexafluoropropylene) electrolyte pouch-type LiPo battery using COMSOL Multiphysics®, and validated results with experimental data. The simulated potential curve exhibited strong agreement with experiment data, while the temperature profile during discharge displayed qualitative discrepancies rationalized by the reversible heat generation. Thermal runaway simulations via oven tests revealed that the highest heat generation is from the cathode–electrolyte reaction, while the solid electrolyte interface decomposition initiates the heat generation process. These results suggest a thorough selection of cathode and electrolyte material to heighten battery safety. Overall, the developed models can be utilized as design tools to investigate various chemistries and designs to estimate the behavior and performance of batteries.

Superhydrophobic, Highly Adhesive, and Corrosion-Protective Fluoropolymer-Modified Polythiophene Coatings

“…The chemical composition of a surface also primarily influences its surface energy. ,, For instance, Zisman et al demonstrated that the surface energy decreases with increasing fluorine content in a polymer, following the sequence: CH 2 > CH 3 > CF 2 > CF 3 . , Fluoropolymers exemplify this principle such that the presence of highly polarized and inert C–F bonds promotes material stability and offers a multifaceted defense mechanism against environmental degradation. − This attribute renders them invaluable for designing insulating layers that promote ionic permeability and prevent electron transfer between the metal and corrosive medium, thereby averting the oxidation process. − Polyvinylidene fluoride (PVDF) and its CF 3 -containing copolymer, PVDF- co -hexafluoropropylene (PVDF–HFP), represent two exemplary fluoropolymers extensively employed in the coating manufacturing industry. Renowned for their exceptional inertness, these polymers offer remarkable corrosion and wear resistance, alongside mechanical integrity, film-forming characteristics, low surface energy, and thermal stability. , The synergy between PVDF’s durability and chemical resistance and HFP’s inclusion promoting ease of processability yields coatings that boast mechanical flexibility, outstanding protective properties, and lower surface energy. , Despite their inherently low surface energy, these fluoropolymers alone cannot achieve superhydrophobicity. , Customizing rough surfaces using materials with low surface energy or generating a rough surface on hydrophobic materials is typically employed to achieve superhydrophobicity.…”