# Amorphous/crystalline interwoven multipods with high Co/Ni activity for wide-temperature-range sodium-sulfur batteries

## TL;DR

Scientists developed a new catalyst that improves the performance of sodium-sulfur batteries across a wide temperature range.

## Contribution

The study introduces Sn-doped CoNiS multipods with amorphous-crystalline interfaces to enhance battery performance.

## Key findings

- The battery achieves 1320.8 mAh g−1 discharge capacity at 3 A g−1 after 1200 cycles at room temperature.
- The catalyst enables stable performance from −20 to 50 °C due to optimized adsorption energy and reduced energy barriers.
- Amorphous-crystalline interfaces improve reaction kinetics by adjusting the microelectronic environment of Co and Ni atoms.

## Abstract

Sluggish kinetics caused by 16-electron transfer hinders development of wide-temperature-range sodium-sulfur batteries. Here we report Sn-doped CoNiS multipods with an amorphous-crystalline interwoven structure. Employed as a positive electrode catalyst, the resulting sodium–sulfur battery exhibits a discharge capacity of 1320.8 mAh g−1 at 3 A g−1 after 1200 cycles at room temperature, together with stable and high-capacity electrochemical performance ranged from −20 to 50 °C. It has been evidenced that the amorphous/crystalline interfaces generated by Sn doping can adjust the microelectronic environment of Co and Ni atoms, optimize their adsorption energy toward sodium polysulfide intermediates through Co–S and Ni–S bonding, and thus decrease the energy barrier of polysulfide conversion. This interfacial regulation efficiently lowers the energy barrier of the rate-determining step and facilitates the overall reaction kinetics over a wide temperature range. This work provides an efficient amorphous/crystalline interface engineering strategy to develop high-performance catalysts.

Slow sulfur redox limits the development of wide-temperature-range Na-S batteries. Here, authors prepare Sn-doped CoNiS multipods catalyst with amorphous–crystalline interfaces that accelerate polysulfides conversion, enabling high-capacity and long-life batteries operated from −20 to 50 °C.