Cyanoethyl cellulose-enabled cathodes with interpenetrating electron transport and ion transport paths via phase inversion method for high energy density lithium metal batteries

Abstract

Binders need to exhibit high bonding strength, sufficient mechanical properties, and electrolyte insolubility to help achieve uniform and stable porous structure and conductive network in electrode composites. Traditional binders like polyvinylidene fluoride offer good electrochemical stability but suffer from poor adhesion performance and weak mechanical flexibility, resulting in unstable electrode structures. To address these issues, a cyanoethyl cellulose-based binder was used to prepare a cyanoethyl cellulose-based cathodes with interpenetrating electron transport and ion transport paths via phase inversion method for high energy density lithium metal batteries. The polar groups (CN, C-O-C, and –OH) on the cyanoethyl cellulose chains could promote the transport of Li-ions through electrostatic interactions. The interpenetrating electron transport and ion transport paths enabled fast Li-ion and electron transport in the cyanoethyl cellulose-based cathodes, resulting in a higher Li-ion diffusion coefficient of to 3.74 × 10−10 cm2·s−1. Hence, the cyanoethyl cellulose-based cathodes enabled batteries with an energy density of 419.8 Wh·kgcathode−1 (mass loading of 16.6 mg·cm−2). This study provided a new strategy to achieve uniform and stable porous structure and conductive network in electrode composites high energy density batteries.