Experimental Temperature and Heat Flux Data for Constant Power Over Heating Tests of 18650 and 26650 LFP Cells.

<p dir="ltr">18650 (1.6 Ah) and 26650 (3.3 Ah) LFP cells were tested under <b>constant-power abuse</b> conditions. Heating was applied using a <b>nickel-chromium</b> high-resistance wire wound around the cell surface. The heating power was set to 40 W and 80 W, respectively, to normalize heating relative to cell size. Battery off-gas was <b>ignited by a continuous spark</b>. A detailed methodology is provided in the related publication [link TBC, insert after publication]; see Figures 1 and 3.</p><p dir="ltr">Cell temperatures, flame temperature, and heat flux were recorded throughout each test. Mass was also measured using a load cell, although readings were affected by signal drift and electromagnetic interference. Therefore, mass loss is reported as the difference between the pre- and post-test measurements.</p><p dir="ltr">Test results are stored in files named<b> </b><code><strong>YYMMDD-000.csv</strong></code>, which can be cross-referenced with sample data in<b> </b><b><i>LFP_ConstPower_Record.xlsx</i></b> (see “<b>Test ID short</b>”). Each CSV file includes cell, flame, and environmental temperatures (°C), cell temperature rate (°C/s), and heat flux (kW/m²). <i>LFP_ConstPower_Record.xlsx</i> contains additional metadata: cell capacity, pre- and post-test mass, cell form, ignition attempt details, and post-test observations. Data is presented from <i>t</i> = 0 s until the heater is switched off or power is lost (in one case, data is truncated shortly after thermal runaway).</p><p dir="ltr">A total of 27 experimental runs were conducted: 23 with 18650 cells (12 with ignitor applied, 11 without ignitor applied) and 4 with 26650 cells (all with ignitor applied).</p><p dir="ltr">Battery safety testing was conducted at the University of Sheffield, with heat flux sensors provided by King’s College London, and the experimental design was developed collaboratively between the two institutions.<br><br>This work was funded by the UKRI through the Faraday Institution's <b>SafeBatt </b>project.</p>