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 isotope144,000,000[ 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-decay2,200,000
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 explosive22.9[ 4]
Hydrogen + oxygen 13.4[ 5]
Gasoline + oxygen 13.3[ citation needed ]
Dinitroacetylene explosive – computed[ citation needed ] 9.8
Octanitrocubane explosive8.5[ 6] 16.9[ citation needed ]
Tetranitrotetrahedrane explosive – computed[ citation needed ] 8.3
Heptanitrocubane explosive – computed[ citation needed ] 8.2
Sodium (reacted with chlorine)[ citation needed ] 7.0349
Hexanitrobenzene explosive7[ 7]
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[ 8] 10.2[ 9]
ANFO –ANNM [ citation needed ] 6.26
Lithium–air battery 6.12
Octogen (HMX)5.7[ 8] 10.8[ 10]
TNT [ 11] 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
ANFO [ citation needed ] 3.7
Hydrogen peroxide decomposition (as monopropellant )2.7 3.8
Li-ion nanowire battery 2.54 29 95%[ clarification needed ] [ 12]
Lithium thionyl chloride battery [ 13] 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
Lithium–sulfur battery [ 14] 1.80[ 15] 1.26
Fluoride-ion battery [ citation needed ] 1.7 2.8
Hydrogen closed cycle fuel cell [ 16] 1.62
Hydrazine decomposition (as monopropellant )1.6 1.6
Ammonium nitrate decomposition (as monopropellant )1.4 2.5
Molten salt 1[ citation needed ] 98%[ 17]
Molecular spring (approximate)[ citation needed ] 1
Lithium metal battery [ 18] [ 19] 0.83-1.01 1.98-2.09
Sodium–sulfur battery 0.72[ 20] [ better source needed ] 1.23[ citation needed ] 85%[ 21]
Lithium-ion battery [ 22] [ 23] 0.46–0.72 0.83–3.6[ 24] 95%[ 25]
Sodium–nickel chloride battery , high temperature[ vague ] 0.56
Zinc–manganese (alkaline) battery , long life design[ 18] [ 22] 0.4-0.59 1.15-1.43
Silver-oxide battery [ 18] 0.47 1.8
Flywheel 0.36–0.5[ 26] [ 27]
5.56 × 45 mm NATO bullet muzzle energy density[ clarification needed ] 0.4 3.2
Nickel–metal hydride battery (NiMH), low power design as used in consumer batteries[ 28] 0.4 1.55
Liquid nitrogen 0.349
Water – enthalpy of fusion 0.334 0.334
Zinc–bromine flow battery (ZnBr)[ 29] 0.27
Nickel–metal hydride battery (NiMH), high-power design as used in cars[ 30] 0.250 0.493
Nickel–cadmium battery (NiCd)[ 22] 0.14 1.08 80%[ 25]
[ 22] 0.13 0.331
Lead–acid battery [ 22] 0.14 0.36
Vanadium redox battery 0.09[ citation needed ] 0.1188 70 70-75%
Vanadium bromide redox battery 0.18 0.252 80%–90%[ 31]
Ultracapacitor 0.0199[ 32] 0.050[ citation needed ]
Supercapacitor 0.01[ citation needed ] 80%–98.5%[ 33] 39%–70%[ 33]
Superconducting magnetic energy storage 0 0.008[ 34] [ bare URL ] >95%
Capacitor 0.002[ 35]
Neodymium magnet 0.003[ 36]
Ferrite magnet 0.0003[ 36]
Spring power (clock spring), torsion spring 0.0003[ citation needed ] 0.0006
Storage type
Energy density by mass (MJ/kg)
Energy density by volume (MJ/L )
Peak recovery efficiency %
Practical recovery efficiency %