Enhanced Li+ ion transport in LiNi0.5Mn1.5O4 through control of site disorder
High voltage spinel LiNi0.5Mn1.5O4 is a very promising cathode material for lithium ion batteries that can be used to power hybrid electrical vehicles (HEVs). In an effort to maximize the performances of high voltage spinel, it is found that the presence of an appropriate amount of oxygen deficiency and/or Mn3+ is critical to accelerate the transport of Li+ ions within the crystalline structure. Through careful control of the cooling rates after high temperature calcination, LiNi0.5Mn1.5O4 spinels with different disordered phase and/or Mn3+ contents have been synthesized. It is revealed that during slow cooling process (<3oC/min), oxygen deficiency is reduced by the oxygen intake, thus residual Mn3+ amount is also decreased in spinels due to charge neutrality. The relative ratio of ordered/disordered phases in high voltage spinels are systematically investigated and finally correlated with Li+ transport phenomena in the lattice through electrochemical evaluation and in-situ XRD technique. LiNi0.5Mn1.5O4 with an appropriate amount of disordered phase or Mn3+ ions offers high rate capability (96 mAh g-1 at 10 C) and excellent cycling performance with 94.8% capacity retention after 300 cycles. The fundamental findings in this work can be widely used to guide the synthesis of other mixed oxides or spinels as high performance electrode materials for lithium ion batteries.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1055401
- Report Number(s):
- PNNL-SA-88177; PPCPFQ; 47414; VT1201000
- Journal Information:
- Physical Chemistry Chemical Physics. PCCP (Print), Vol. 14, Issue 39; ISSN 1463-9076
- Publisher:
- Royal Society of Chemistry
- Country of Publication:
- United States
- Language:
- English
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