Interfacial Phonon Scattering Enables Ultrastable and High-Power Sodium-Based Dual-Ion Batteries With Alloying Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Alloying anodes in sodium-based dual-ion batteries (SDIBs) offer high energy density but suffer from rapid degradation due to strain energy from volume changes.
• Conventional interfacial designs often fail by cracking or delamination, accelerating battery failure.

Purpose of the Study:

• To develop a novel interfacial strategy for managing strain energy in alloying anodes for SDIBs.
• To enhance the cycle life and durability of high-energy SDIBs.

Main Methods:

• A crystal-plane friction interface (CPFI) was constructed by embedding Na+-substituted α-zirconium phosphate (NZrP) nanoparticles into a polymer matrix on a Sn anode.
• In situ stress measurements were used to quantify strain energy reduction.
• Electrochemical performance was evaluated in SDIB full cells.

Main Results:

• The CPFI strategy effectively relieved strain energy through facile sliding between NZrP (002) planes, reducing strain energy density by 99.1%.
• Na+ substitution in NZrP facilitated rapid ion transport, decreasing interfacial impedance by approximately 65%.
• Sn@CPFI anodes enabled SDIB full cells retaining over 80% capacity after 3500 cycles at 5C and 90.1% retention at 40C.

Conclusions:

• Crystal-plane sliding is established as a general mechanism for managing strain energy in electrodes with high volume changes.
• The CPFI strategy offers a promising pathway toward durable, high-energy SDIBs with improved cycle life.