Numerous research and development initiatives have focused on improving pseudocapacitive materials and associated energy storage devices due to their well-known high capacitance and high-rate capabilities. The extensive use of nanomaterials in batteries, however, has recently allowed for the achievement of fast redox kinetics that are on par with pseudocapacitive materials. The main reason for this is that the nanoscale effects lead to shorter ion diffusion lengths and more surface or interface exposure. Since then, the line between “battery materials” and “pseudocapacitive materials” has become increasingly harder to draw. This review starts by looking at several ways that pseudocapacitive materials have been defined, how these definitions have changed over time, and how confused people have been as a result. A suggested technique that uses quantitative kinetics analysis in conjunction with electrochemical signatures such as cyclic voltammetry (CV) and galvanostatic charge discharge (GCD) can distinguish between the battery and pseudocapacitive materials with high accuracy. Lastly, the review wraps up by delving into possible setups for asymmetric and hybrid supercapacitors. This review hopes that the differences between battery materials and pseudocapacitive materials will help to clear up any misunderstandings about what they are and how they differ.