Fully reversible lithium storage of tin oxide enabled by self-doping and partial amorphization.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Tin dioxide (SnO2) offers high theoretical capacity for lithium-ion battery anodes.
• Achieving full reversibility and stable cycling in SnO2 anodes is challenging due to sluggish kinetics.

Purpose of the Study:

• To develop a fully reversible SnO2 anode for lithium-ion batteries.
• To enhance the rate and cycling capabilities of SnO2-based anodes.

Main Methods:

• Synthesized a nanocomposite by anchoring SnO2 nanoparticles onto a graphene/single-walled carbon nanotube hybrid framework.
• Utilized self-doping and partial amorphization of SnO2.
• Investigated the electrochemical performance and cycling stability of the composite anode.

Main Results:

• The composite anode (74% SnO2) demonstrated high reversible capacities, retaining 1215 mA h g-1 after 200 cycles at 0.1 A g-1.
• Achieved 947 mA h g-1 at 1 A g-1 with 98% retention over 350 cycles.
• Exceptional performance attributed to the formation of metallic Sn in Li2O matrix via a two-step lithiation mechanism.

Conclusions:

• A novel strategy for creating fully reversible SnO2 anodes for lithium-ion batteries was demonstrated.
• The self-doped, partially amorphous SnO2 anchored on a hybrid framework offers superior electrochemical performance.
• This approach is applicable to developing other high-performance conversion-type electrodes.