Enhancing electro-chemo-mechanical properties of Micro-scale SiOx anode via an interactive graphene/Carboxymethyl cellulose composite network for high-performance Lithium-ion batteries

Abstract

Micron-sized SiO_x anodes are gaining attention due to their improved cycling stability compared to Si anodes. However, they still face challenges related to volume expansion, which can compromise electrode integrity. To address this, a composite binder of graphene and carboxymethyl cellulose (Gr/CMC) was introduced to enhance the mechanical and electrochemical stability of SiO_x electrodes. The strong interactions between Gr and CMC promote uniform distribution of electrode materials, which minimizes localized stress, reduces particle agglomeration, and maintains stable connectivity across the electrode. This uniformity supports consistent reactions and alleviates strain from volume expansion, preserving electrode structure and contributing to extended cycle life. The SiO_x anode with the Gr/CMC binder demonstrated excellent electrochemical performance, including high reversible capacity, enhanced rate capability, and notable durability, achieving 86 % capacity retention over 300 cycles in a pouch-type full cell (3.5 mAh cm⁻², 85 wt% SiO_x anode). This study highlights the critical role of the Gr/CMC composite binder in ensuring superior performance of anodes with a high SiO_x content, offering a promising approach for high-capacity lithium-ion batteries.