Fabrication and mechanistic study of AP/nAl/PTFE spherical encapsulated energetic materials with enhanced combustion performance

•AP/nAl/PTFE composite was prepared by EISA method with isolated encapsulating unit.•Enhanced combustion performance was obtained for the encapsulated composites.•Composite with 15 wt% content of PTFE showed the optimum combustion performance.•The generated acid and F gases could etch the Al2O3 shell to expose more active Al.