Comparison of the performance of different battery technologies for electricity storage

U ovome radu opisani su različiti sustavi za pohranu električne energije te su objašnjene glavne karakteristike svakog pojedinog sustava. Elektrokemijski sustavi za pohranu električne energije (baterije) detaljnije su opisani i uspoređeni s obzirom na glavne karakteristike svake pojedine tehnologije baterije. U sklopu praktičnog dijela u Laboratoriju za obnovljive izvore energije na Fakuletetu elektrotehnike, računarstva i informacijskih tehnologija provedena su mjerenja za tri vrste Li-ion baterija: Panasonic NCR18650B, LG 18650HG2 te SONY US18650VTC5 i jednu vrstu NiMH baterija: Panasonic eneloop pro BK-3HCDE. Objašnjen je način punjenja/praţnjenja Li-ion baterija (CC-CV način punjenja/praţnjenja) te princip rada uređaja korištenog za provedbu mjerenja. Prikazana je grafička analiza mjernih rezultata te je analiziran utjecaj različitih faktora C prilikom procesa punjenja/praţnjenja na napon, struju, snagu i energiju punjenja/praţnjenja te stanje energije i povratnu učinkovitost na svaku pojedinu Li-ion bateriju. Na osnovu grafičke analize zaključeno je da su najbolji rezultati povratne učinkovitosti dobiveni kod mjerenja sa faktorom 0,2C punjenja/praţnjenja. Usporedbom utjecaja različitih faktora C punjenja/praţnjenja na povratnu učinkovitost različitih tipova Li-ion baterija zaključeno je da SONY US18650VTC5 baterija ima najbolju povratnu učinkovitostThis thesis describes different electricity storage systems and explains the main characteristics of each system. Electrochemical systems for storing electricity (batteries) are described in more detail and compared with regard to the main characteristics of each individual battery technology. As part of the practical part in the Laboratory for Renewable Energy Sources at the Faculty of Electrical Engineering, Computing and Information Technology, measurements were performed for three types of Li-ion batteries: Panasonic NCR18650B, LG 18650HG2 and SONY US18650VTC5 and one type of NiMH batteries: Panasonic eneloop pro BK-3HCDE. The method of charging/discharging Li-ion batteries (CC-CV mode of charging / discharging) and the principle of operation of the device used to perform the measurement are explained. A graphical analysis of the measurement results is presented and the influence of various C – rates during the charging/discharging process on the voltage, current, power and energy of the charging/discharging and the state of energy and round trip efficiency on each individual Li-ion battery is analyzed. Based on the graphical analysis, it was concluded that the best round trip efficiency results were obtained when measuring with a 0.2C charge/discharge rate. By comparing the influence of different charge/discharge C - rates on the round trip efficiency of different types of Li-ion batteries, it was concluded that the SONY US18650VTC5 battery has the best round trip efficiency