# A Review of Experimental and Numerical Studies of Lithium Ion Battery Fires
## 3 LIB Chemistry
### Cathode and Anode  
The two most critical parameters when evaluating the performance of a LIB are the power/energy density and capacity. The energy density of a device is the product of the specific capacity of the material used in the electrodes and the operational voltage from the cathode to the anode [27]. A significant number of studies have been conducted on the structure of the electrode materials. The specific capacity of the common materials used has been fully exploited with most new research exploring the electrochemical potentials of materials to produce batteries with higher voltages, due to the greater difference in lithium chemical potential between the cathode and anode.  
LIB materials largely consist of insertion-type or intercalation electrodes, meaning lithium cations (Li\({}^{+}\)) are merged into a host structure and upon charge and discharge the Li\({}^{+}\) is reversibly merged via intrinsic one, two- or three-dimensional openings to facilitate the Li\({}^{+}\) transport without \"in theory\" any significant change to the host structure. Insertion/intercalation materials are predominantly used due to the high cycling capacity and the minimal variation in volume changes between the discharged and charged states of the cathode and anode. The negative aspect of the insertion/intercalation material is the need for the host structure which is essentially \"excess baggage\" and thus, reduces the energy density of the cell [28; 29]. Alternatively, alloying and conversion mechanisms are also utilized whereby in the case of alloying Li\({}^{+}\) is inserted into the crystal structure of the  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Component** & **Common Composition** \\ \hline \multirow{2}{*}{Anode} & Graphitic carbons, hard carbons, synthetic graphite, LTO, tin-based alloys, silicon-based alloys \\ \hline \multirow{2}{*}{Cathode} & LMO, LCO, NCA, NMC, LFP, ECPs \\ \hline \multirow{2}{*}{Electrolyte} & Lithium salts (mostly LiPF\({}_{6}\)) in organic solvents such as EC, DEC, DMC, PC, GBL, RTILs \\ \hline \multirow{2}{*}{Separator} & Polypropylene, polyethylene, cellululosic paper, nonwoven fabrics, ceramic \\ \hline \multirow{2}{*}{Current Collector} & Copper for anode \\ \cline{2-2}  & Aluminum for cathode \\ \hline \hline \end{tabular}
\end{table}
Table 1: Typical components of lithium-ion batteries (LIBs) and their compositions [19].  
electrode (direct bonding with the host structure) in the reactant phase. The conversion mechanism has Li-ions inserted into the nanosized binary compounds resulting in a reduction of cations and the formation of Li anions. The benefits of the alloying and the conversion mechanisms are the high energy density, relatively low cost, environmental compatibility, and the safe operation potentials [30]. The main disadvantages are the short cycle life and the irreversible loss of capacity due to the large volume expansion during the insertion of lithium ions [30]. The repeated expansion and reduction have been shown to cause fracturing of the electrode material, effectively disconnecting portions within the electrode. Additionally, dendrite formation across the cells and through the separator leading to internal short circuit (ISC) caused by electrochemical plating is an on-going concern as the mechanism of dendrite growth is still very much under debate [27; 31].