The development of environmentally friendly methods for producing and storing sustainable energy is highly important. Therefore, the integration of a renewable energy generation and energy storage system results in high-energy and high-density power sources. Hence, the development of an integrated photovoltaic (PV)-battery system is of high interest. Lithium-ion batteries (LIBs) are among the most promising energy storage systems and utilizing LIBs in a PV-battery system can reduce the use of fossil fuels for electricity production and the need for charging stations [1], [2].
Graphite (Gr) is a commonly used anode in LIBs due to its long cycle life and low cost, however, its low theoretical capacity of 372 mAh/g limits its usage in high-energy battery applications. Silicon (Si) on the other hand, has a high theoretical capacity of 3590 mAh/g at room temperature; however, Si goes through a huge volume change (≥280%) upon charge/discharge. Therefore, developing Si/Gr blend anodes with suitable polymeric binders can bring the synergistic benefits of Si and Gr active material together[3]. In this work, LIBs with Si/Gr blend anode and NMC 622 cathode were investigated to be used in a PV-battery system. The cells were electrochemically characterized at room temperature as well as high temperatures (45 °C and 60 °C) and suitable electrolyte additives such as fluoroethylene carbonate (FEC), Vinylene Carbonate (VC), and silane-based additives[4] were used to improve the performance of the cells at high temperatures. In addition to the electrochemical measurements, the electrodes were characterized with a scanning electron microscope (SEM) after being cycled at different temperatures. The cell’s capability of integration in a PV-battery system was investigated in solar charging experiments with a perovskite solar cell.