Engineering the direct deposition of Si nanoparticles for improved performance in Li-ion batteries

Abstract

In our efforts to address the issues of Si based anodes for Li ion batteries, such as limited active mass loading, rapid capacity degradation and low scalability in manufacturing, we reported a scalable, high mass loading, and additive-free Si nanoparticles (NP) deposition based electrode, but the achieved capacity and cycle life were still limited. In order to improve the reversible capacity and cycling stability of this Si NP deposition electrode, in this work, we have investigated various substrates for Si deposition, including carbon paper (CP), preheated CP and stainless steel felt/mesh (SSF/SSM), and their influences on the electrochemical Li-ion storage performance of the Si NP electrodes. Meanwhile, protective encapsulations of amorphous carbon or silicon nitride on Si NP has been performed and the capabilities of these coatings in improving the cycling stability of Si NP electrodes have been researched. It is found that a carbon-coated Si NP deposition on an SSM substrate achieves an extraordinary cycling stability in electrochemical Li-ion storage for 500 cycles with an average capacity loss of 0.09% per cycle, showing significantly improved commercial viability of Si NP deposition based electrodes in high-energy-density Li-ion batteries.