High energy chelating coating improves the combustion performance and propellant compatibility of AL-5Li alloy powder

Aluminum-lithium alloy powder fuel is commonly used as a propellant because of its high combustion energy and energy-release level. However, the high reactivity of Li leads to poor compatibility of the Al-Li alloy powder with other propellant composites. In this study, a chelate of carboxymethyl cellulose sodium (CMC) and aluminum ions, with high viscosity and a large number of hydroxyl groups, was prepared and coated onto the surface of an Al-Li alloy powder. The high-energy compound azide glycidyl ether (GAP) was further introduced onto the surface via a synergistic interaction with the Al³⁺-CMC chelate, forming layer-by-layer coated aluminum–lithium-based fuel Al-5Li@CMC@GAP. The combustion heat, ignition properties, and thermal stability of the fuel were enhanced after the coating. The combustion heat of Al-5Li@CMC@GAP increased by 9.98 % compared to that of the raw Al-5Li powder. In addition, Al-5Li@CMC@GAP burned with bright flames with a shorter combustion duration. The dense coating layer of Al-5Li@CMC@GAP was maintained even after aging for 3 months in the propellant. Therefore, Al-5Li@CMC@GAP can be used as an alloy fuel in composite solid propellants with good compatibility and storage durability and will play an important role in aviation and defense fields.