Binder-free CNT cathodes for Li-O$_2$ batteries with more than one life

TL;DR

This paper presents a simple method to create binder-free, flexible CNT electrodes for Li-O2 batteries that can be reconditioned and reused, enhancing battery lifespan and sustainability.

Contribution

The study introduces a novel, easy fabrication process for binder-free CNT electrodes that are recyclable and maintain performance over multiple cycles.

Findings

Electrodes exhibit high porosity, conductivity, and flexibility.

Reconditioning effectively removes discharge products without performance loss.

Electrodes can be reused multiple times, reducing costs and environmental impact.

Abstract

Li-O$_2$ batteries (LOB) performance degradation ultimately occurs through the accumulation of discharge products and irreversible clogging of the porous electrode during the cycling. Electrode binder degradation in the presence of reduced oxygen species can result in additional coating of the conductive surface, exacerbating capacity fading. Herein, we establish a facile method to fabricate free-standing, binder-free electrodes for LOBs in which multi-wall carbon nanotubes (MWCNT) form cross-linked networks exhibiting high porosity, conductivity, and flexibility. These electrodes demonstrate high reproducibility upon cycling in LOBs. After cell death, efficient and inexpensive methods to wash away the accumulated discharge products are demonstrated, as reconditioning method. The second life usage of these electrodes is validated, without noticeable loss of performance. These findings aim to assist in the development of greener high energy density batteries while reducing manufacturing and recycling costs.