# A Review of Experimental and Numerical Studies of Lithium Ion Battery Fires
## 5 Heat Release Rate
### HRR Data Other than Cone Calorimeter  
A series of propane fire tests conducted by [PERSON] [86] sought to evaluate HRR, toxic species emission, and cell temperature. The LIBs used in the six abuse studies contained a LFP cathode and a carbon-based anode and to give a comparative example, a single test on a laptop battery with a cobalt-based cathode. These tests involved the use of an SBI apparatus used in accordance with the European Classification Scheme EN13823, which is generally used for the classification of building materials. The heat flux was provided by a propane burner placed under the cells and produced approximately 15 kW. The test objects and details are provided in Table 13.  
The experimental results for tests 1-5 indicate that the cell at 100% SOC reaches a peak HRR, which far exceeds that of the cells at 50% SOC and 0% SOC. Additionally, the time to the first peak of the cell at 100% SOC is considerably faster than the first and maximum HRR peaks of the cells at 50 and 0%. The results of tests 6 and 7 show that the Lenovo laptop battery pack reaches its peak HRR value faster and has a greater magnitude than the cylindrical K2 cells. It should be noted that the laptop battery packs in this particular test consisted of additional materials, i.e., battery housing and electronic circuits, which may have contributed to these results. \begin{table}
\begin{tabular}{c|c|c|c} \hline \hline
**Condition (SOC) and Radiative Heat Source** & **Time to Peak HRR (s)** & **Normalized HRR (kW m-2)** \\ \hline \(0\%-50\) kW m\({}^{-2}\) & & 265.67 & NP \\ \(30\%-50\) kW m\({}^{-2}\) & & 329.01 & NP \\ \(50\%-50\) kW m\({}^{-2}\) & & 295.08 & \(\sim\)710 \\ \(80\%-50\) kW m\({}^{-2}\) & & 265.35 & NP \\ \(100\%-50\) kW m\({}^{-2}\) \(\blacktriangledown\) & & 213.12 & NP \\ \hline \(0\%-75\) kW m\({}^{-2}\) & & 79.73 & 307.14 \\ \(30\%-75\) kW m\({}^{-2}\) & & 110.39 & 589.20 \\ \(50\%-75\) kW m\({}^{-2}\) & & 81.34 & 1056.95 \\ \(80\%-75\) kW m\({}^{-2}\) & & 86.00 & 814.49 \\ \(100\%-75\) kW m\({}^{-2}\) \(\blacktriangledown\) & & 78.98 & 848.55 \\ \hline \(50\%-25\) kW m\({}^{-2}\) & & NP & 557.80 & \\ \(50\%-35\) kW m\({}^{-2}\) & & NP & \(\sim\)705 & \\ \(50\%-50\) kW m\({}^{-2}\) & & 295.08 & \(\sim\)710 & \\ \(50\%-75\) kW m\({}^{-2}\) \(\blacktriangledown\) & & NP & 1056.95 \(\blacktriangledown\) \\ \hline \hline \end{tabular}
\end{table} 
Table 11: HRR versus SOC for 18650 NMC LIBs [85]. \begin{table}
\begin{tabular}{c|c|c|} \hline \hline
**Battery Chemistry and SOC (\%)** & **HRR\({}_{\text{max}}\) (kW)** & **Normalized HRR\({}_{\text{max}}\) (kW m-2)** \\ \hline \multicolumn{3}{c}{LCO} \\ \hline \(0\) & 2.6 & 621.1 & \\ \(25\) & 4.1 & 979.9 \\ \(50\) & 4.9 & 1171.1 & \\ \(75\) & 5.6 & 1338.4 & \\ \(100\blacktriangledown\) & 4.1 \(\blacktriangledown\) & 979.9 \(\blacktriangledown\) \\ \hline \multicolumn{3}{c}{LFP} \\ \hline \(0\) & 2.0 & 478.0 & \\ \(50\) & 5.2 & 1242.8 & \\ \(100\blacktriangledown\) & 8.3 \(\blacktriangledown\) & 1983.7 \(\blacktriangledown\) \\ \hline \hline \end{tabular}
\end{table} 
Table 12: HRR versus SOC for 18650 LCO and LFP LIBs [87] at 20 kW m\({}^{-2}\). A full-scale burning test (based on the ISO 9705 full-scale room fire apparatus) of high-energy 50 Ah LFP/graphite battery packs (composed of five identical 10 Ah single cells) was conducted by [PERSON] [88]. The battery dimensions were 91 mm long, 66 mm wide, and 140 mm high, giving a total surface area of 559.72 cm\({}^{2}\). The results of [PERSON] [88] presented in Table 14 indicate that the LIB at 100% SOC had the largest peak HRR and the battery at 0% had the lowest HRR. The times to the peak HRR are quite comparable, though the higher SOC tends to peak before the LIB at a lower SOC. Experimental work on the combustion behavior of LFP/graphite batteries exposed to an external heat source was also conducted by [PERSON] [66]. Electric vehicle 50 Ah batteries were investigated in the ISO 9705 room. The radiant heat source was provided by a 3 kW electric heater.