Work

Failure Characteristics of Cylindrical Cells (18650 and 26700) Across Sodium-Ion, Lithium Nickel Manganese Cobalt Oxide (NMC), Lithium Iron Phosphate (LFP) and Lithium Titanate (LTO) Chemistries

Year: 2026
Type: article
Abstract: This study compares the failure characteristics of four 1.5 Ah 18650 cells, including lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), lithium titanate (LTO), and sodium-ion (NFM), alongside a 3 Ah 26700 NFM cell. Cells at a 100% state of charge (SoC) were evaluated using three types of failure methods. Open-field external heat testing was used to characterise visible failure behaviour, including venting, flames, and sparking. Accelerating rate calorimetry (ARC) provided high-resolution temperature data for key failure points, including venting onset, thermal runaway (TR), and peak temperature. Pressure vessel tests under an inert atmosphere enabled quantification of total gas volume and analysis of major gas species (H2, CO2, CO, and light hydrocarbons). Three open-field results for each cell type showed no ignition in any LTO or LFP tests, while NMC and NFM cells were ignited in one and two tests, respectively. ARC measurements found that LTO exhibited the lowest TR onset temperature, while that of LFP exceeded 130 °C, with NMC and NFM cells falling between. Pressure vessel results indicated that when gas volumes were normalised to L/Ah, NFM2 cells generated the largest volume of gas, and 1.23 L/Ah and NMF1 cells generated the least (0.59 L/Ah). LFP cells showed the highest H2 concentration, with LTO producing minimal gas. These findings highlight the need for application-specific assessment of cell chemistry safety.
Source: Batteries
Language: English
Open Access status: gold
Estimated APC paid: $3,258
OpenAlex ID: W7220448291
FWCI:
Cites: 31
Cited by:
Related to: 10