Storage type Specific energy (MJ /kg) Energy density (MJ/L ) Peak recovery efficiency % Practical recovery efficiency % Arbitrary Antimatter 89,875,517,874 depends on density Deuterium–tritium fusion 576,000,000 [ 1] Uranium-235 fissile isotope 144,000,000 [ 1] 1,500,000,000 Natural uranium (99.3% U-238, 0.7% U-235) in fast breeder reactor 86,000,000 Reactor-grade uranium (3.5% U-235) in light-water reactor 3,456,000 35% Pu-238 α-decay 2,200,000 Hf-178m2 isomer 1,326,000 17,649,060 Natural uranium (0.7% U235) in light-water reactor 443,000 35% Ta-180m isomer 41,340 689,964 Metallic hydrogen (recombination energy) 216 [ 2] Specific orbital energy of Low Earth orbit (approximate) 33.0 Beryllium + Oxygen 23.9 [ 3] Lithium + Fluorine 23.75[ citation needed ] Octaazacubane potential explosive 22.9 [ 4] Hydrogen + Oxygen 13.4 [ 5] Gasoline + Oxygen –> Derived from Gasoline 13.3[ citation needed ] Dinitroacetylene explosive - computed[ citation needed ] 9.8 Octanitrocubane explosive 8.5 [ 6] 16.9 [ 7] Tetranitrotetrahedrane explosive - computed[ citation needed ] 8.3 Heptanitrocubane explosive - computed[ citation needed ] 8.2 Sodium (reacted with chlorine)[ citation needed ] 7.0349 Hexanitrobenzene explosive 7 [ 8] Tetranitrocubane explosive - computed[ citation needed ] 6.95 Ammonal (Al+NH4 NO3 oxidizer )[ citation needed ] 6.9 12.7 Tetranitromethane + hydrazine bipropellant - computed[ citation needed ] 6.6 Nitroglycerin 6.38 [ 9] 10.2 [ 10] ANFO -ANNM [ citation needed ] 6.26 battery, Lithium–air 6.12 Octogen (HMX) 5.7 [ 9] 10.8 [ 11] TNT [ 12] 4.610 6.92 Copper Thermite (Al + CuO as oxidizer )[ citation needed ] 4.13 20.9 Thermite (powder Al + Fe2 O3 as oxidizer ) 4.00 18.4 Hydrogen peroxide decomposition (as monopropellant ) 2.7 3.8 battery, Lithium-ion nanowire 2.54 29 95%[ clarification needed ] [ 13] battery, Lithium Thionyl Chloride (LiSOCl2) [ 14] 2.5 Water 220.64 bar, 373.8 °C[ citation needed ] [ clarification needed ] 1.968 0.708 Kinetic energy penetrator [ clarification needed ] 1.9 30 battery, Lithium–Sulfur [ 15] 1.80 [ 16] 1.26 battery, Fluoride-ion [ citation needed ] 1.7 2.8 battery, Hydrogen closed cycle H fuel cell [ 17] 1.62 Hydrazine decomposition (as monopropellant ) 1.6 1.6 Ammonium nitrate decomposition (as monopropellant ) 1.4 2.5 Thermal Energy Capacity of Molten Salt 1[ citation needed ] 98% [ 18] Molecular spring approximate[ citation needed ] 1 battery, Lithium–Manganese [ 19] [ 20] 0.83-1.01 1.98-2.09 battery, Sodium–Sulfur 0.72 [ 21] 1.23[ citation needed ] 85% [ 22] battery, Lithium-ion [ 23] [ 24] 0.46-0.72 0.83-3.6 [ 25] 95% [ 26] battery, Sodium–Nickel Chloride , High Temperature 0.56 battery, Zinc–manganese (alkaline) , long life design [ 19] [ 23] 0.4-0.59 1.15-1.43 battery, Silver-oxide [ 19] 0.47 1.8 Flywheel 0.36-0.5 [ 27] [ 28] 5.56 × 45 mm NATO bullet muzzle energy density[ clarification needed ] 0.4 3.2 battery, Nickel–metal hydride (NiMH) , low power design as used in consumer batteries [ 29] 0.4 1.55 Liquid Nitrogen 0.349 Water – Enthalpy of Fusion 0.334 0.334 battery, Zinc–Bromine flow (ZnBr) [ 30] 0.27 battery, Nickel–metal hydride (NiMH) , High-Power design as used in cars [ 31] 0.250 0.493 battery, Nickel–Cadmium (NiCd) [ 23] 0.14 1.08 80% [ 26] battery, Zinc–Carbon [ 23] 0.13 0.331 battery, Lead–acid [ 23] 0.14 0.36 battery, Vanadium redox 0.09[ citation needed ] 0.1188 70 70-75% battery, Vanadium–Bromide redox 0.18 0.252 80%–90% [ 32] Capacitor Ultracapacitor 0.0199 [ 33] 0.050[ citation needed ] Capacitor Supercapacitor 0.01[ citation needed ] 80%–98.5% [ 34] 39%–70% [ 34] Superconducting magnetic energy storage 0 0.008 [ 35] >95% Capacitor 0.002 [ 36] Neodymium magnet 0.003 [ 37] Ferrite magnet 0.0003 [ 37] Spring power (clock spring), torsion spring 0.0003 [ 38] 0.0006 Storage type Energy density by mass (MJ/kg) Energy density by volume (MJ/L ) Peak recovery efficiency % Practical recovery efficiency %