1. Fluorinated Electrolytes for High-Energy Ni-rich NCA90 Lithium-Ion Batteries at a Cylindrical Cell Configuration: A Deep Dive into Decomposition Pathways
Kan Homlamai, Thitiphum Sangsanit, Ronnachai Songthan, Worapol Tejangkura, and MontreeSawangphruk
ChemSusChem 2025, e202500238
DOI : 10.1002/cssc.202500238
Abstract : This study investigates the electrochemical performance, stability, and decomposition mechanismsof fluorine-based electrolytes in large-scale cylindrical Ni-rich lithium-ion batteries (LIBs) underhigh-voltage conditions (up to 4.8 V). We examine fluoroethylene carbonate (FEC) and di-fluoroethylene carbonate (DFEC) in electrolyte formulations and their effects on battery longevity,gas evolution, and solvation dynamics. While FEC is known for improving the solid electrolyteinterphase (SEI), DFEC remains underexplored. Using molecular dynamics (MD) simulations,density functional theory (DFT) calculations, and electrochemical analysis, we identify keysolvation properties, ion transport characteristics (tLi⁺, CIP%), and electronic structuresinfluencing electrolyte stability. The 1.2 M LiPF₆ in DMC/FEC/DFEC (4:0.5:0.5% v/v) electrolyte achieves the highest capacity retention (85.11% after 1,000 cycles), with DFEC reducing solvationshell binding energy and stabilizing electrolyte performance. Differential electrochemical massspectrometry (DEMS) and nuclear magnetic resonance (NMR) spectroscopy reveal that FEC leadsto higher CO₂ production via ring-opening and de-fluorination to vinylene carbonate (VC), whileDFEC reduces gas evolution. These insights provide a holistic framework for optimizing high-energy electrolyte formulations, supporting the development of safer, more efficient LIBs forelectric vehicles and energy storage applications.
2. Layered lithium- and manganese-rich oxide cathode cells in large-scale cylindrical configuration: Optimized electrolyte formulations with LiDFOB and LiBF₄ Co-additives for enhanced stability
Thitiphum Sangsanit, Nuttida Matkhaw, Nurulsafeelanaria Benwannamas, Ronnachai Songthan, Worapol Tejangkura, Montree Sawangphruk
Journal of Power Sources, 2025, 632, 236337.
DOI : 10.1016/j.jpowsour.2025.236337
Abstract : Layered lithium- and manganese-rich oxide (LMR-NMC) cathodes are emerging as frontrunners for next-generation lithium-ion batteries, offering exceptional specific capacities (>245 mAh/g) and high operating voltages (>4.7 V). However, their widespread adoption is hindered by severe electrolyte decomposition, exacerbated by lattice oxygen release and high voltage cycling, especially in large-scale cylindrical cells with thick electrodes. In this study, we provide the first comprehensive analysis of gas- and liquid-phase electrolyte decomposition in LMR-NMC//graphite 18650 cylindrical cells. We identify ethylene carbonate (EC)-induced degradation pathways, including excessive water generation during initial cycling, driven by reactions with active oxygen. To address these challenges, we propose an EC-free electrolyte formulation incorporating lithium difluoro(oxalato)borate (LiDFOB) and lithium tetrafluoroborate (LiBF₄) as co-additives. These additives effectively stabilize the cathode-electrolyte interphase (CEI), suppress oxygen-induced degradation, and dramatically enhance long-term cell stability. This optimized electrolyte design paves the way for scalable, high-energy LMR-NMC cathodes in commercial lithium-ion battery applications.
3. Investigation of Capacitance Degradation in Activated Carbon Supercapacitors Subjected to Cryogenic Conditions
Apichanont Limsukhon, Thitiphum Sangsanit, Worapol Tejangkura, Adisorn Tuantranont and Montree Sawangphruk
Journal of The Electrochemical Society, 2025, 172, 010515.
DOI : 10.1149/1945-7111/ada73f
Abstract : This study examined the electrochemical performance of 18650 cylindrical supercapacitors subjected to a cryogenic temperature at −196 °C. Cylindrical supercapacitor cells, utilizing 1 M tetraethylammonium tetrafluoroborate (TEABF4) in acetonitrile as the electrolyte, were immersed in liquid nitrogen. Results indicated a 6.4% decrease in capacitance following exposure. To identify the cause of this reduction, we analyzed the surface chemistry of the electrodes and electrolyte degradation using X-ray photoelectron spectroscopy and proton nuclear magnetic resonance (¹H NMR), respectively. No significant changes were detected in either the surface chemistry or electrolyte. Instead, the capacitance reduction was linked to the higher activation energy required for electric double-layer adsorption/desorption, as described by the Arrhenius equation. This effect is attributed to the deformation of the styrene-butadiene rubber (SBR) binder because −196 °C is much lower than its glass transition temperature of −50 °C. At −196 °C, the SBR transitions from a flexible, rubbery state to a brittle, glassy state can cause the SBR to crack or shatter, thereby reducing the adhesive contact between the current collector and the active materials. These findings highlight the importance of polymer binders in ensuring long-term stability, especially for supercapacitors intended for low-temperature environments.
4. Microbubble synthesis of hybridised bacterial cellulose–gelatin separators for multifunctional supercapacitors
Surachai Chaichanaa, Pawin Iamprasertkun bc, Montree Sawangphruk d, Noelia Rubio e and Pichamon Sirisinudomkit
The Royal Society of Chemistry, 2025.
DOI : 10.1039/d4se01684j
Abstract : Separators are known to be a mandatory component due to their crucial function in preventing short circuits between positive and negative electrodes, ensuring the safety and cycle life of energy storage devices. However, in practice, separators are a crucial component that affects cell electrochemical performance, especially rate capability and power density, which have been addressed in only a few research studies. To further investigate this topic, this study introduces durable and eco-friendly separators synthesised by hybridising bacterial cellulose (BC) and gelatin through a facile, cost-effective, desirable and environmentally friendly microbubble process. The as-fabricated symmetric supercapacitor with an as-synthesised separator, prepared under optimal conditions of 2 g per mL BC with 1.5 wt% gelatin and a microbubble rate of 200 CC per min (designated as 2BC1.5GT_R200), reduces cell resistance and optimises ion transport within the cell compared to as-fabricated symmetric supercapacitors using BC, hybridised BC–gelatin under other conditions, conventional cellulose and commercial separators. Additionally, symmetric devices with 2BC1.5GT_R200 separators achieve excellent capacitance retention across a wide range of electrolyte environments, including acidic (1 M H2SO4), basic (1 M KOH), and neutral (1 M NaNO3) solutions, retaining over 91%, 87%, and 82% of their initial capacitance after 10 000 cycles, respectively. These data demonstrate that the microbubble synthesis process combined with gelatin hybridisation can maximise electrochemical performance, maintain high cell efficiency, and enable operation in diverse electrolytes, presenting a promising route for developing innovative separators for energy storage applications.