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Published on: November 11, 2013
Calcium Gradient-Doped LiNi0.5Mn1.5O4 Cathode for Long Cycle Life Lithium-Ion Batteries
Jie Xiong1, Emmanuel Kornyo1, Bingyao Zhou1
1Department of Chemical and Paper Engineering, Western Michigan University, 4601 Campus Drive, Kalamazoo, Michigan 49008-5462, United States.
ACS Applied Energy Materials
|May 15, 2026
Summary
Calcium gradient doping enhances lithium-ion battery performance by stabilizing LiNi0.5Mn1.5O4 (LNMO) cathodes. This method improves capacity retention and rate capability, addressing key limitations for next-generation batteries.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- High-voltage spinel LiNi0.5Mn1.5O4 (LNMO) is promising for next-generation lithium-ion batteries (LIBs).
- LNMO's practical use is hindered by capacity decay from structural instability and interfacial reactions.
- Manganese dissolution is a key issue affecting LNMO cathode longevity.
Purpose of the Study:
- To enhance the structural and surface stability of LNMO cathodes using gradient doping with calcium (Ca).
- To investigate the effects of Ca gradient doping on the electrochemical performance of LNMO in LIBs.
- To elucidate the mechanisms behind the improved performance in gradient-doped LNMO.
Main Methods:
- Gradient doping of LNMO with calcium.
- Characterization using electronic microscopy, X-ray diffraction, and elemental analysis.
- Electrochemical testing including cyclic voltammetry, differential capacity, and electrochemical impedance spectroscopy.
Main Results:
- Ca preferentially segregates to the surface in gradient-doped LNMO, creating a disordered bulk structure.
- Ca gradient-doped LNMO cathodes show higher capacities (∼126-130 mAh/g) and Coulombic efficiencies (88-95%) than uniformly doped or undoped samples.
- Ca gradient-doped LNMO exhibits superior rate capability (∼113 mAh/g at 10 C) and cycling stability (∼96.3% retention after 500 cycles).
Conclusions:
- Gradient doping with Ca effectively stabilizes LNMO cathodes by enhancing the oxygen framework and surface properties.
- The disordered bulk structure facilitates fast Li+ diffusion, while the Ca-enriched surface suppresses Mn dissolution.
- Ca gradient doping offers a promising strategy to overcome the limitations of LNMO for advanced LIB applications.
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