The rapid evolution of energy storage technology has necessitated the exploration of alternatives to conventional Li-ion batteries. It is driven by the limitations of resource scarcity, safety concerns, and sustainability challenges. This chapter critically discusses the technical, economic, and environmental aspects of emerging battery technologies. While Li-ion batteries are instrumental in powering electronics, electric vehicles, and renewable energy systems, their reliance on limited lithium and cobalt deposits, flammability risks, and recycling hurdles necessitate the development of next-generation solutions. A compelling alternative is solid-state batteries based on non-flammable ceramic, polymer, and glasses. These batteries feature enhanced safety, higher energy density, and improved thermal stability. These parameters satisfy applications in vehicles. Yet, challenges related to manufacturing scalability, interfacial resistance, and cheap production persist. Na-ion batteries gain researchers’ attention due to the low cost of sodium. Despite their lower energy density compared to Li-ion, recent advancements in cathode and anode materials can decrease the performance gap. Another promising avenue is lithium-oxygen and zinc-air systems. The latter offer theoretical energy densities surpassing the ones of Li-ion systems. Oxygen management, electrolyte degradation, and limited cycle life remain limiting barriers. Redox flow batteries, particularly vanadium and organic redox flow systems, provide scalable solutions for long-duration performance, though their bulkiness and lower energy density eliminate their compatibility with tablets and smartphones. Mg , Ca , and Al ions are cheap and offer high theoretical capacities. A slow-ion kinetics must be dealt with in the future. Organic and biodegradable batteries leverage eco-friendly materials and designs, while their current performance limitations restrict them to niche applications. Presently, Li-ion remains the dominant player due to its established infrastructure and cost-effectiveness. Therefore, recycling and sustainability efforts, such as closed-loop recovery systems and ethical sourcing initiatives, are critical in minimizing the ecological footprint of Li. Technological optimizations and machine-learning optimizations are essential for the future of energy storage and portable devices.