Innovations in battery technology have produced materials that substantially improve performance and longevity. Key advances include doped and coated composite cathodes enhancing sodium-ion and lithium-ion battery stability, novel polymer electrolytes for solid-state applications, and oxygen-vacancy-rich samarium-doped composites for supercapacitors. Research also highlights enhanced electrochemical behaviors in magnesium deposition and lithium manganese iron phosphate cathodes. Together, these pioneering materials are paving the way towards safer, more efficient, and durable energy storage systems critical for renewable energy and electric vehicle adoption.