Advanced 1D SWCNT-interwoven hybrid electrode architecture for enhanced electrochemical performance in Na-seawater batteries

Abstract

The demand for rechargeable batteries with high-energy density has driven innovations in cell design and materials. One such innovation is the development of a metal-free seawater battery that uses seawater to store sodium ions indefinitely. However, its performance is limited by the need for further advancements in the electrode architectures of both the anode and cathode. In this study, a new class of hybrid electrode architectures for seawater batteries, consisting of a fibrous nanomaterial hard carbon (FNHC) anode and a one-dimensional (1D) bucky paper (1DBP) cathode, based on 1D building block-interwoven hetero-nanomaterial frameworks, is demonstrated. The electrodes are fabricated using dual electrospraying and electrospinning for the anode and vacuum-assisted infiltration for the cathode, resulting in a hetero-nanomaterial framework. For the FNHC anode, hard carbon particles are embedded in reinforced polymeric nanofiber/carbon nanotube (CNT) skeletons to construct three-dimensional ion/electron pathways, eliminating the need for heavy aluminum foil collectors. The highly reticulated CNT networks provide well-interconnected electronic pathways for the 1DBP cathode. The electrochemical performance of the FNHC/1DBP seawater full-cell is exceptional, with a specific energy density of 693 W h kg⁻¹ and a specific power density of 3341 W kg⁻¹, exceeding the capabilities of innovative next-generation battery technologies.