Lithium Storage in Heat-Treated SnF2 /Polyacrylonitrile Anode
Lian Shen1, Lanyao Shen1, Zhaoxiang Wang2
1Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy Materials and Device, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (P. R. China).
Chemistry (Weinheim an Der Bergstrasse, Germany)
|May 1, 2015
Summary
Heat-treated tin(II) fluoride (SnF2) electrodes exhibit high lithium-ion storage capacity through conversion and alloying reactions. This enhanced electrode design demonstrates excellent reversible capacity over 100 cycles, promising for advanced battery applications.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Tin(II) fluoride (SnF2) is a promising anode material for lithium-ion batteries due to its high theoretical lithium storage capacity.
- SnF2 storage mechanisms involve both conversion reactions and Li/Sn alloying/dealloying.
- Improving the electrical contact and mechanical stability of SnF2 electrodes is crucial for practical applications.
Purpose of the Study:
- To enhance the electrochemical performance of SnF2 anodes for lithium-ion batteries.
- To investigate the effect of a cross-linked polyacrylonitrile (PAN) binder and heat treatment on SnF2 electrode properties.
- To understand the lithium storage mechanisms in the modified SnF2 electrode.
Main Methods:
- Preparation of a polyacrylonitrile (PAN)-bound SnF2 electrode.
- Heat treatment of the PAN-SnF2 electrode to induce cross-linking and improve structural integrity.
- Electrochemical testing, including cyclic voltammetry and galvanostatic cycling, to evaluate lithium storage capacity and cycling stability.
Main Results:
- The heat-treated SnF2 electrode demonstrated a high initial reversible capacity of 1047 mAh g(-1).
- The electrode maintained a reversible capacity of 902 mAh g(-1) after 100 cycles, indicating good cycling stability.
- Excess capacity was attributed to lithium storage at the Sn/LiF interface and potential reduction of SnF2 by protons from PAN cross-linking.
Conclusions:
- Heat treatment of PAN-bound SnF2 electrodes effectively enhances electrical contact and mechanical strength.
- The modified SnF2 electrode exhibits superior lithium storage performance and stability for battery applications.
- The study elucidates key factors contributing to the enhanced capacity in SnF2-based anodes.
