Robust artificial interphases constructed by a versatile protein-based binder for high-voltage Na-ion battery cathodes

Abstract

The multiple issues of unstable electrode/electrolyte interphases, sluggish reaction kinetics, and transition-metal (TM) dissolution have long greatly affected the rate and cycling performance of cathode materials for Na-ion batteries. Herein, a multifunctional protein-based binder, sericin protein/poly(acrylic acid) (SP/PAA), is developed, which shows intriguing physiochemical properties to address these issues. The highly hydrophilic nature and strong H-bond interaction between crosslinking SP and PAA leads to a uniform coating of the binder layer, which serves as an artificial interphase on the high-voltage Na4Mn2Fe(PO4)2P2O7 cathode material (NMFPP). Through systematic experiments and theoretical calculations, it is shown that the SP/PAA binder is electrochemically stable at high voltages and possesses increased ionic conductivity due to the interaction between sericin and electrolyte anion ClO4−, which can provide additional sodium-migration paths with greatly reduced energy barriers. Besides, the strong interaction force between the binder and the NMFPP can effectively protect the cathode from electrolyte corrosion, suppress Mn-dissolution, stabilize crystal structure, and ensure electrode integrity during cycling. Benefiting from these merits, the SP/PAA-based NMFPP electrode displays enhanced rate and cycling performance. Of note, the universality of the SP/PAA binder is further confirmed on Na3V2(PO4)2F3. It is believed that the versatile protein-based binder is enlightening for the development of high-performance batteries.

Ke Cheng

Postdoctoral Researcher

My research interests lie at the surface of chemistry and biology, where I am deeply passionate about applying innovative chemistry to advance fields such as chemoproteomics, drug discovery, nanomedicine, and theranostics. My aim is to provide robust methodologies for mapping biological interactomes, accelerating drug development, and expanding therapeutic opportunities.