# Economic Analysis of Potential Secondary Use of Batteries from Electric Vehicles
## 2 Battery Life Cycle  
The battery in an electric vehicle (EV) is one of the most important components of the entire construction. Mostly, it is the battery that decides on the most important parameters of EV, which include the total range per charge and the final price. Lithium batteries with various heavy metal additives (Co, Cd, Ni, Zn, etc.) are mainly used in today's EVs [2]. The beginning of the battery life cycle begins in the mines with the mining of lithium and heavy metals. The largest deposits of lithium itself are in Australia and Chile, cobalt deposits in the Democratic Republic of the Congo and manganese deposits in China and South Africa [3]. To illustrate the number of used materials and their prices in the Chevrolet Bolt EV battery see Table 1.  
According to Table 1, it is obvious that concerning the required number of raw materials, the most expensive is cobalt, followed by graphite and nickel. One ton of lithium is more than a ton of graphite or nickel, but it has a very low percentage in the battery. Aluminum is the most consumed, the price of which is much lower than that of the above-mentioned materials. The actual production of battery cells is currently taking place mainly in China, the USA, Korea and Japan. Examples are the A123 System, Samsung, LG, Panasonic and Tesla. Subsequently, the manufactured batteries are used in various electrical devices around the world. One of the biggest uses is in the field of electromobility. To give an idea of how many batteries are needed in the EU alone to meet CO2 limits, it is worth mentioning EU regulations that require car manufacturers to produce only 95 g of carbon dioxide per kilometer by 2021, otherwise, car manufacturers will be forced to pay a corresponding fine. By 2030, automotive companies should offer at least 35% of EVs from their total manufacturing number [5]. According to [6], it is declared that the battery will reach the end of life if its capacity is reduced by 20% of the original capacity. Maintaining such a high capacity means that \begin{table}
\begin{tabular}{c c c} \hline \hline
**Material** & **Percent of Battery Cell Mass (\%)** & **Cost Per Ton (€)** \\ \hline Aluminum & 16 & 1345 \\ \hline Graphite & 14 & 8408 \\ \hline Steel & 13 & 504 \\ \hline Iron & 9 & 62 \\ \hline Copper & 8 & 5337 \\ \hline Cobalt & 6 & 22,700 \\ \hline Nickel & 6 & 8408 \\ \hline Manganese & 5 & 1430 \\ \hline Polyester & 3 & N/A \\ \hline Lithium & 2 & 12,612 \\ \hline Other & 18 & N/A \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Representation of materials in the battery and its prices of Chevrolet Bolt EV [4]. some of the materials, most bulk materials, are still active in the battery, so it is appropriate to explore the possibilities for using batteries after the first life cycle. Based on [7], the first life battery can also be briefly defined as the use of the battery until its capacity is reduced from 100% to 80%. As reported by [7], the definition of a second life battery consists in the use of the battery from the time when the capacity goes from 80% to 66-60% of the starting value. The potential of the battery cells in EV is not used to 100%. This is mainly due to the degradation of capacity and the directly dependent reduction in vehicle mileage. One of the parameters of the battery is the number of charging cycles (CCs), which the battery is capable of before it is taken out of service resp. the battery is exhausted. Battery exhaustion means that the battery drops below 60% of capacity. Some data on traction batteries for EVs show a drop value below 30-50% [8]. Battery life is reduced primarily by loading the battery with high currents. For example, during a drive with repeated rapid acceleration, the actual energy output from the battery is always lower. The chemical structure of the battery fails to emit as much current as if it were discharged slowly. Battery life is also related to operating temperature.