# Lithium Metal: The Key to Green Transportation
### Lithium Sources  
The major sources of lithium are contained in three main deposit types: pegmatites, continental brines, and hydrothermally altered clays [49]. Chile contains 41% of global reserves and is located within brine lake and salt crust deposits (sometimes called salars) [50; 51]. Due to numerous faults and volcanic eruptions presented in the Chile region [49], it estimates to have a huge reserve of up to 120 thousand square kilometers [51]. Brines with a lithium high concentration of about 0.3% are found in the Salars of Chile, Bolivia, and Argentina, while lower concentrations are found in the United States (such as Kings Mountain Belt, Smackover, Salton Sea, Great Salt Lake, etc.) [52] and the Tibetan Plateau [26; 53]. Pegmatites formed as a result of the crystallization of magma at depth in the crust and have considerable lithium deposits, like in Australia [52]. It can also be recovered from clays [54; 55] in various ratios using techniques described in [PERSON] et al. [26], and seawater [54; 55] using an adsorption technique [56] and other techniques described in [26; 56]. However, the recovered lithium concentration in seawater is relatively small at 0.17 ppm compared to that of salars between 1000-3000 ppm [26].  
Many sources report different reserve estimates. The assumption of different studies estimates a range of 4-30 million tons [54; 57]. The highest estimate was in 2011 when they estimated 39 million tons [54], but the most recent data of 2022 estimated a rounded number of 22 million tons [41]. This difference in estimation is due to the feasible assumption of lithium recovery that is different from one researcher to another. [PERSON] [58] doubted the estimation method by saying that some of the calculation methods used are overvalued due to the use of hard rock deposit guidelines in estimating brine resources. He argued that resources may turn into reserves following the advancement of extraction and production technology. Based on the three main types of lithium deposits (pegmatite and spodumene, mineralized springs, and salar sediments) with a grade range of between 1% and 2.31%, there is an estimated 1.27 million tons of Li\({}_{2}\)O. All these deposits are available in Afghanistan and can probably make Afghanistan the global lithium mining hub [26]. Countries with reserves and their mineral deposits are listed in Table 3.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Country** & **Main Mineral** & **Formula** & **Lithium Content (\%)** \\ \hline Afghanistan & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ Australia & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ Austria & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ Brazile & Petalite & LiAlSi\({}_{4}\)O\({}_{10}\) & 2.09 \\  & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ Canada & pegmatites & Unspecified & 0.49 \\  & petalite & LiAlSi\({}_{4}\)O\({}_{10}\) & 2.09 \\  & Lepidolite & KL\({}_{2}\)Al(Al,Si)\({}_{3}\)O\({}_{10}\)(F,OH)\({}_{2}\) & 3.58 \\ China & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\  & petalite & LiAlSi\({}_{4}\)O\({}_{10}\) & 2.09 \\ DRC & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ Finland & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ Mali & Amblygonite & (Li,Na)AlPO\({}_{4}\)(F,OH) & 3.44 \\ Portugal & Petalite & LiAlSi\({}_{4}\)O\({}_{10}\) & 2.09 \\ Namibia & Petalite & LiAlSi\({}_{4}\)O\({}_{10}\) & 2.09 \\  & pegmatites & not specified & 0.49 \\ Russia & Lepidolite & KL\({}_{2}\)Al(Al,Si)\({}_{3}\)O\({}_{10}\)(F,OH)\({}_{2}\) & 3.58 \\  & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ Serbia & Jadarite & LiNaSi\({}_{3}\)O\({}_{7}\)(OH) & 3.16 \\ Spain & Lepidolite & KL\({}_{2}\)Al(Al,Si)\({}_{3}\)O\({}_{10}\)(F,OH)\({}_{2}\) & 3.58 \\ Sweden & spodumene & LiAlSi\({}_{2}\)O\({}_{6}\) & 3.73 \\ \hline \end{tabular}
\end{table}
Table 3: Main lithium-bearing minerals that have greater lithium content by countries. Adapted from [18].