Energy storage batteries for electric aircraft face unprecedented challenges: extreme weight sensitivity, high power demands, and rigorous safety standards. Unlike ground transportation, aircraft batteries must balance energy density (to maximize flight range) with safety (to prevent in-flight fires), while withstanding vibration, temperature fluctuations, and high altitudes. These constraints have spurred innovation in battery chemistry, thermal management, and structural integration, driving the development of next-generation energy storage for eVTOL (electric vertical takeoff and landing) aircraft, regional electric planes, and hybrid-electric airliners.  

Lithium-ion batteries with high energy density are the current standard, with chemistries like lithium nickel cobalt aluminum (NCA) or lithium nickel manganese cobalt (NMC) offering up to 300–400 Wh/kg. For example, the Eviation Alice, an all-electric commuter plane, uses a 2.8 MWh NMC battery pack weighing ~2.3 tons, enabling a 250-mile range. Advanced cell designs, such as pouch cells or prismatic cells, optimize space and weight, while carbon fiber casings provide structural support and fire resistance. Thermal management is critical: liquid-cooled plates with non-flammable dielectric fluids maintain cell temperatures within 25–40°C, preventing thermal runaway. Some systems even use phase-change materials (PCMs) for passive cooling during emergencies.  

Safety protocols exceed terrestrial applications. Aircraft batteries must pass rigorous tests like FAA’s TSO-C174b, which mandates fire containment for at least 15 minutes to allow emergency landing. Multilayer safety systems include:  

Fire-resistant barriers between cells to prevent cascading failures.  

Pressure-sensitive vents that release gas without rupturing the casing.  

Redundant BMS with triple-layer voltage/temperature monitoring.  

Lithium fire suppression systems using inert gases like nitrogen.  

Future advancements aim to double energy density via silicon anodes or solid-state electrolytes. Solid-state batteries, with non-flammable ceramic or polymer electrolytes, could reach 500–600 Wh/kg while eliminating liquid electrolyte risks, making them ideal for commercial aviation. As electric aviation transitions from small eVTOLs to larger aircraft, energy storage systems will need to balance range, payload, and safety, driving innovations that may eventually disrupt traditional jet fuel dependency.