Advanced Na-NiCl₂ Battery Using Nickel-Coated Graphite with Core-Shell Microarchitecture.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Stationary electric energy storage is crucial for renewable energy integration and grid stability.
• Sodium-based batteries offer advantages over lithium-ion due to abundant sodium resources.
• Sodium-nickel chloride (Na-NiCl2) batteries face challenges with high material costs (nickel) and degradation at operating temperatures.

Purpose of the Study:

• To design a cost-effective and stable sodium-nickel chloride battery.
• To address the high nickel content and operating temperature limitations of conventional Na-NiCl2 batteries.
• To improve the performance of stationary sodium-based energy storage systems.

Main Methods:

• Development of a core-shell microarchitecture: nickel-coated graphite.
• Utilizing a graphite core to preserve surface area and structural integrity.
• Characterization of the new material for energy density and efficiency.

Main Results:

• A core-shell microarchitecture using 40% less nickel compared to conventional Na-NiCl2 batteries.
• Achieved an initial energy density of 133 Wh/kg at approximately C/4 rate.
• Demonstrated an energy efficiency of 94% at an intermediate temperature of 190 °C.

Conclusions:

• The nickel-coated graphite design offers a promising pathway for cost reduction in sodium-nickel chloride batteries.
• The developed material maintains electrochemical activity and structural integrity at reduced nickel content.
• This advancement supports the viability of sodium-nickel chloride batteries for stationary energy storage applications.