Electronic voting systems face many challenges, including authentication, privacy, data integrity, transparency and verifiability. However, the developed over 10 years ago blockchain technology provides an out-of-the-box solution for many of those challenges. Despite that, some issues are still to be solved, like remote authentication, anonymity and end-to-end verifiability. For this reason, research on new and better blockchain-based systems is still ongoing. The main goal of this study is to highlight the current trends in this research and its eventual shortcomings. This was accomplished by conducting a Systematic Literature Review (SLR) (Kitchenham and Charters, 2007), which resulted in selecting 35 publications. The performed SLR allowed to define trends in utilized blockchain technologies, intended scenarios, testing methods, main benefits and challenges faced by various systems and the most used cryptographic solutions.