Manipulating Interphase Chemistry by Endogenous Doping Toward High-Performance Hard Carbon Anodes for Sodium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Hard carbon (HC) anodes in sodium-ion batteries suffer from poor initial coulombic efficiency (ICE), cycling stability, and rate performance.
• These limitations are linked to interphase chemistry and microstructure, hindering practical application.

Purpose of the Study:

• To develop a strategy for manipulating interphase chemistry and microstructure in HC anodes.
• To enhance the performance of HC anodes for sodium-ion batteries through endogenous doping.

Main Methods:

• Utilized a Maillard reaction triggered by reducing sugars and amino acids for endogenous N/S doping.
• Engineered microstructural design and interphase chemistry of HC anodes.
• Fabricated and tested HC anodes in sodium-ion battery configurations.

Main Results:

• Achieved an inorganic-enriched solid-electrolyte interface (SEI) layer, accelerating ion transport and reducing side reactions.
• Demonstrated a reversible capacity of 363 mAh g^-1 at 0.05 A g^-1 and superior cycling stability (79% retention over 2500 cycles at 5.0 A g^-1).
• Reported an adequate ICE of 89% and excellent performance in full cells and pouch cells with high mass loading.

Conclusions:

• Endogenous N/S doping is an effective strategy for simultaneously addressing key performance limitations in HC anodes.
• The developed HC anodes show significant potential for high-performance sodium-ion batteries.
• This approach offers new insights for designing advanced HC anode materials.