Nano Silicon Composite with Gelatin/Melamine Derived N-doped Carbon as an Efficient Anode Material for Li-ion Batteries

Abstract

Silicon (Si) has a high theoretical capacity and low working potential vs. Li/Li<sup>+</sup>, and has been investigated as the most capable negative electrode material for lithium-ion batteries (LIBs). However, Si undergoes significant volume changes during the Li<sup>+ </sup>alloying/ dealloying processes, leading to unstable cycle life and limiting its practical applicability in anodes. Introducing carbon into the Si anodes can effectively address the Si drawbacks, while providing advantages of improved conductivity and structural stability. In this study we choose gelatin/ melamine combination as an eco-friendly and cost-effective source for nitrogendoped carbon to make a Si composite. The prepared composite was studied as an anode material for LIBs, and it delivered excellent cyclability with 2175 mAh g<sup>-1</sup> capacity after 50 cycles with 86% capacity retention at 200 mA g<sup>-1</sup>. The composite exhibited superior rate capability and improved Li<sup>+</sup> diffusion properties compared with bare Si nanoparticles (Si NP). The significant enhancement could be attributed to the structural stability and conductivity provided by the nitrogen-doped carbon matrix. This work promotes emerging batteries with low-cost materials as a promising solution for increasing energy storage requirements.