Porous-dual-shell structure and heterojunction Co₃O₄@NiCo₂O₄ accelerating polysulfides conversion for all-solid-state...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium-sulfur batteries (ASSLSBs) offer high energy density potential but face challenges.
• Key issues include poor ionic conductivity, low Li+ transference number, and inefficient lithium polysulfide (LiPSs) conversion.

Purpose of the Study:

• To address the limitations of ASSLSBs by developing a new composite material.
• To enhance ionic conductivity, Li+ transference, and LiPSs conversion for improved battery performance.

Main Methods:

• Preparation of a porous-dual-shell Co3O4@NiCo2O4 heterojunction.
• Composite of the heterojunction with polyethylene oxide (PEO)-based solid polymer electrolytes (SPEs).
• Characterization of electrochemical properties, including ionic conductivity and LiPSs conversion.

Main Results:

• The Co3O4@NiCo2O4 heterojunction creates superimposed electric fields that improve Li salt dissociation and ionic conductivity.
• Achieved high ionic conductivity (1.04 × 10^-3 S/cm) and Li+ transference number (0.48) at 60 °C.
• Demonstrated stable Li//Li cell performance for 1100 hours and significant reversible capacity in Li//S cells (620.1 mAh/g after 100 cycles).

Conclusions:

• The Co3O4@NiCo2O4 heterojunction effectively enhances ASSLSB performance.
• The material facilitates fast LiPSs conversion and improves electrochemical kinetics.
• This advancement contributes to the development of next-generation high-energy-density batteries.