Topology optimization (TO) has emerged as a prominent trend in recent years, driven by its ability to explore optimized material distributions from scratch. Recently, there has been a significant shift in the application of TO, in optimizing systems involving complex electrochemical reactions, particularly electrode porous structures. This paper aims to examine the utilization of TO in enhancing electrodes across various electrochemical devices. It encompasses a broad spectrum of applications, including the optimization of porous electrodes through the density-based method and interfaces between electrodes and electrolytes through the level-set method. The paper will delve into the challenges and opportunities associated with employing TO in electrode design for electrochemical devices. These challenges involve addressing computational complexity, the absence of theoretical foundations for optimized structures, and the fabrication of complex structures for practical real-world applications. Additionally, beyond TO, the paper will spotlight other notable techniques in the structural design of porous electrodes using mathematical optimization. By offering insights into state-of-the-art research and developments in TO's application to electrode design, this paper provides researchers with valuable resources to navigate the evolving landscape of electrode design for electrochemical energy devices.