Metal Sulfide Applications in Sodium-Ion Energy Storage

Metal sulfides have emerged as leading candidates for sodium-ion battery electrodes due to their high theoretical capacity, low cost and earth abundance. As conversion-type materials, transition metal sulfides such as copper sulfide (CuS), molybdenum disulfide (MoS₂) and iron sulfide (FeS) deliver capacities well above 400 mAh g⁻¹ through multi-electron redox processes. Their layered or porous nanostructures facilitate fast sodium-ion insertion (intercalation) and conversion reactions, while mitigating volume expansion. Advances in heterostructure design, phase engineering and carbon or polymer coatings have enhanced electrical conductivity and cycle life. Key challenges remain in controlling phase transitions—such as irreversible amorphisation—and stabilising the solid electrolyte interphase under repeated sodiation. Recent work has demonstrated that built-in electric fields at nanoscale interfaces can trigger desirable phase transformations in MoS₂, while elastic buffering layers on CuS dramatically improve rate capability. Collectively, these strategies point towards scalable, durable sodium-ion energy storage systems capable of grid-scale and portable applications.

Research from Nature Portfolio

Atomic-scale observation of copper sulfide nanoplates has revealed a non-equilibrium sodiation pathway comprising four distinct crystalline phases, including a short-lived metastable structure. In situ transmission electron microscopy demonstrated that each phase evolution directly correlates with voltage plateaus in the discharge profile. This work establishes copper sulfide as a near-theoretical-capacity anode (~560 mAh g⁻¹) with long-term cyclability, and provides the first detailed mapping of intercalation-conversion mechanisms at the atomic level.

Metal Sulfide Applications in Sodium-Ion Energy Storage publication trend

The graph below shows the total number of articles in metal sulfide applications in sodium-ion energy storage across all publications each year (not limited to Nature Index journals).

Technical terms

Intercalation: Insertion of sodium ions into a host lattice without complete structural breakdown.

Conversion reaction: Redox process where a metal sulfide transforms into elemental metal and sodium sulfide.

Sodiation: Incorporation of sodium ions into an electrode material during battery discharge.

Heterostructure: Engineered interface between distinct materials designed to tailor electronic or ionic transport.

Solid electrolyte interphase (SEI): A passivation layer formed by electrolyte decomposition that stabilises the electrode surface.

References

1. Electronic Modulation and Built‐in Electric Field Strategies in Heterostructures Together Induce 1T‐Rich MoS2 Conversion for Advanced Sodium Storage. Advanced Science (2025).
2. Atomic visualization of a non-equilibrium sodiation pathway in copper sulfide. Nature Communications (2018).
3. Elastic Buffering Layer on CuS Enabling High-Rate and Long-Life Sodium-Ion Storage. Nano-Micro Letters (2022).
4. Copper Sulfide and Graphite Felt Composites as Promising Electrode Materials for Sodium-Ion Batteries. ACS Applied Materials & Interfaces (2024).