Enhanced Electrochemical Performance of Silicon-Based Anode Material Via a Synergistic Effect Between Sodium Alginate and Dopamine Hydrochloride

Abstract

Silicon (Si) material, which has the advantages of good safety and high capacity, is expected to replace the commercial graphite as the next generation anode material for lithium ion batteries (LIBs) application. Herein, we developed a strategy to largely enhance the cycling stability and rate performance of the Si-based material. In that, sodium alginate (SA) was employed as a coating material. As a result, both of the cycling stability and rate performance of the material were effectively enhanced. For instance, the SA-coated Si(O) showed capacity enhancement of 28.2%, 26.6%, 49.1% and 115% as compared to the bare one at the current densities of 100 mA g−1, 250 mA g−1, 500 mA g−1 and 1000 mA g−1, respectively. Moreover, a synergistic effect between SA and dopamine hydrochloride (PDA) was discovered, which effectively impeded the drastically capacity degradation in the beginning several cycles at various current densities, leading to excellent rate performance of the Si(O)/SA–PDA material. The calculated specific capacity of this material reached as high as 3440 mAh g−1 at 50 mA g−1 by excluding the energy storage contribution from the graphite in the electrode. Importantly, both SA and PDA coatings were completed by a simply ball-milling method. Altogether, this work bears significant meaning to the actual application of Si-based material in LIBs field.