A Dual-Functional Artificial Interphase Design for High-Efficient and Long-Duration Anode-Free Sodium All-Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Anode-free solid-state sodium batteries (AFSSBs) offer high energy density and cost benefits but face challenges like sodium dendrite formation and interfacial issues.
• Existing strategies struggle with rigid interfaces, volume expansion, and reactivation of inactive sodium, hindering practical AFSSB deployment.

Purpose of the Study:

• To systematically investigate sodium morphology evolution at the interface between a copper current collector and Na5SmSi4O12 (NSSO) solid electrolyte.
• To design and implement a dual-functional iodinated polymeric elastic artificial interphase layer (I-PIL) to address key AFSSB challenges.

Main Methods:

• Investigated sodium deposition morphologies on Cu/NSSO interfaces.
• Developed an iodinated polymeric elastic artificial interphase layer (I-PIL) using photoinitiated polymerization.
• Tested Na|Cu half-cells and full AFSSBs with Na3V2(PO4)3 cathodes.

Main Results:

• The I-PIL ensured conformal interfacial contact and reactivated dead sodium via I3- reaction.
• Na|Cu half-cells demonstrated excellent cycling stability with 99.7% Coulombic efficiency over 1000 hours at 1.5 mA cm-2.
• AFSSBs retained 85.8% capacity after 2000 cycles at 1.0 mA cm-2 and 92.8% over three months under high mass loading (28 mg cm-2).

Conclusions:

• The study provides fundamental insights into sodium deposition mechanisms in AFSSBs.
• The developed I-PIL offers a versatile and scalable strategy for enhancing interfacial stability and performance in anode-free solid-state batteries.
• This work advances the development of high-performance, durable next-generation energy storage.