The Investigation of Thermal Stability of Na 3 V 2 (PO 4 ) 2 F 3 /Hard Carbon Cylindrical Cells Using Accelerating Rate Calorimetry
Year: 2026
Type: article
Abstract: Na 3 V 2 (PO 4 ) 2 F 3 (NVPF) is a promising cathode material for sodium-ion batteries (SIBs) because of its structural robustness, high operating voltage, fast Na + transport, and stable electrochemical performance, and NVPF/hard carbon (HC) is well established as a high-rate chemistry. However, its full-cell thermal behavior remains insufficiently understood. Here, the exothermic behavior of NVPF/HC 18 650-format cylindrical cells is systematically investigated at 100%, 75%, and 50% state of charge (SOC) using accelerating rate calorimetry (ARC). NVPF/HC cells employing polyvinylidene fluoride (PVDF)- or carboxymethyl cellulose (CMC)-binder in HC anodes are further evaluated by long-term cycling and ARC and benchmarked against LiFePO 4 (LFP)/graphite cells. NVPF/HC cells exhibit strong SOC-dependent thermal behavior, with higher SOC leading to earlier and more intense exothermic reactions. Both NVPF/HC and LFP/graphite cells retain ∼94% of their initial capacity after ∼200 cycles at 40 °C with limited growth in voltage polarization. Fresh and aged NVPF/HC cells exhibit similar thermal characteristics regardless of HC binder chemistry. After cycling, NVPF/HC and LFP/graphite cells exhibit distinct thermal behavior: while LFP/graphite cells show a slightly lower self-heating rate, NVPF/HC cells reach a much lower termination temperature (∼180 °C, beyond which no self-heating is detected) compared to ∼270 °C for LFP/graphite cells.
Institutions: University of North Carolina at Chapel Hill, University of Maryland, College Park, University of North Carolina at Charlotte, Centre National de la Recherche Scientifique, Réseau sur le Stockage Electrochimique de l'énergie, Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, Collège de France, Chimie du Solide et Energie
Language: English
Subfield: Automotive Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W7222357086