Next-generation energy storage technologies are at the forefront of enabling a sustainable, electrified future, with solid-state batteries (SSBs) and supercapacitors (SCs) emerging as two of the most promising solutions. SSBs replace conventional liquid electrolytes with solid ones, allowing the use of lithium-metal anodes that deliver higher energy density, improved safety, and extended cycle life, positioning them as potential game changers for electric vehicles and grid-scale applications. Meanwhile, SCs bridge the gap between capacitors and batteries by offering exceptional power density, ultrafast charge–discharge rates, and remarkable longevity, making them ideal for applications requiring rapid energy delivery, such as regenerative braking, backup power, and wearable electronics. Despite significant progress, both technologies face challenges—SSBs in terms of manufacturing scalability and interface stability, and SCs in cost-effective material development. Together, these advancements highlight a complementary pathway, where hybrid integration of SSBs and SCs could redefine the future of safe, efficient, and versatile energy storage systems.