Spray Drying Method for Large-Scale and High-Performance\nSilicon Negative Electrodes in Li-Ion Batteries

Abstract

Nanostructured\nsilicon electrodes have shown great potential as\nlithium ion battery anodes because they can address capacity fading\nmechanisms originating from large volume changes of silicon alloys\nwhile delivering extraordinarily large gravimetric capacities. Nonetheless,\nsynthesis of well-defined silicon nanostructures in an industrially\nadaptable scale still remains as a challenge. Herein, we adopt an\nindustrially established spray drying process to enable scalable synthesis\nof silicon–carbon composite particles in which silicon nanoparticles\nare embedded in porous carbon particles. The void space existing in\nthe porous carbon accommodates the volume expansion of silicon and\nthus addresses the chronic fading mechanisms of silicon anodes. The\ncomposite electrodes exhibit excellent electrochemical performance,\nsuch as 1956 mAh/g at 0.05C rate and 91% capacity retention after\n150 cycles. Moreover, the spray drying method requires only 2 s for\nthe formation of each particle and allows a production capability\nof ∼10 g/h even with an ultrasonic-based lab-scale equipment.\nThis investigation suggests that established industrial processes\ncould be adaptable to the production of battery active materials that\nrequire sophisticated nanostructures as well as large quantity syntheses.