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Updated: Jun 20, 2026
10:41
The Effect of Charging and Discharging Lithium Iron Phosphate-graphite Cells at Different Temperatures on Degradation
Published on: July 18, 2018
Pulsed Charging-Induced Interfacial Stabilization Enables Highly Stable Iron Phosphate Electrode for Ultrafast
Ziquan Wang1, Zhujie Liang1, Yongbing Tang2
1College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, People's Republic of China.
Angewandte Chemie (International Ed. in English)
|June 18, 2026
Summary
A new pulsed charging method enhances electrochemical lithium extraction from salt lake brines by protecting iron phosphate electrodes from magnesium ion damage. This method improves lithium recovery efficiency and product purity.
Area of Science:
- Materials Science
- Electrochemistry
- Chemical Engineering
Background:
- Global lithium demand necessitates efficient extraction methods.
- Electrochemical lithium extraction using iron phosphate (FePO4) electrodes faces challenges in high Mg2+/Li+ ratio brines.
- Magnesium ion (Mg2+) intercalation degrades FePO4 electrodes by weakening bonds, causing Fe2+ dissolution and Fe2O3 formation.
Purpose of the Study:
- To elucidate the degradation mechanism of FePO4 electrodes in Mg2+-rich brines.
- To develop a novel strategy for protecting FePO4 electrodes and enhancing lithium extraction.
- To improve the efficiency and purity of lithium chloride (LiCl) production from salt lake resources.
Main Methods:
- Investigated Mg2+ intercalation effects on FePO4 electrode structure and bonding.
- Proposed and implemented a pulsed charging protocol with reverse potentials.
- Utilized cyclic voltammetry, electrochemical impedance spectroscopy, and ICP-OES for analysis.
- Tested FePO4||Ag cells in simulated and real salt lake brine environments.
Main Results:
- Demonstrated Mg2+ intercalation weakens Fe-O bonds, leading to Fe2+ dissolution and Fe2O3 formation.
- The pulsed charging protocol effectively removed Mg2+ and enriched Cl- on the electrode surface.
- Achieved high Li+ extraction kinetics (approx. 20 mg g-1 h-1).
- Obtained high LiCl product purity (99.95%) and excellent cycling stability (800 hours, ~80% retention).
Conclusions:
- The pulsed charging protocol offers a robust strategy for high-efficiency electrochemical lithium extraction.
- This approach provides a theoretical basis for protecting electrodes in challenging brine compositions.
- The findings pave the way for advancing sustainable lithium recovery from unconventional sources.
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