Spray pyrolysis of yolk–shell particles and their use for anodes in lithium-ion batteries

•Spray pyrolysis is compatible with the production of yolk–shell structure.•We demonstrate this for the case of nickel oxide (shell)–silicon (yolk) particles.•After annealing, these particles can be used as anodes for lithium-ion batteries.•Performance: 1400 mAh/g at 0.5 C for 100 cycles

We demonstrate the synthesis of yolk–shell particles using spray-pyrolysis, a technique with proven scalability to industrial production level. Nickel oxide (shell)–silicon (yolk) particles are produced using a single-step aerosol reaction from a mixture of commercial, off-the-shelf precursors. After coating and annealing in the presence of polyvinylpyrrolidone, the nickel oxide shell is converted into a porous nickel cage enclosing the silicon particles. The polymer decomposition leads to the formation of an amorphous carbon layer surrounding the nickel cage. This structure maintains a high specific discharge capacity after more than 100 cycles (~ 1400 mAh/g at the 110th cycle with a 0.5 C discharge rate, on a silicon basis) when used as anode for lithium-ion batteries.