TY - JOUR
T1 - Theoretical capacity achieved in a LiMn0.5Fe0.4Mg0.1BO3 cathode by using topological disorder
AU - Kim, Jae Chul
AU - Seo, Dong Hwa
AU - Ceder, Gerbrand
N1 - Publisher Copyright:
© The Royal Society of Chemistry 2015.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - Simple borates are attractive cathodes for lithium-ion batteries due to two main reasons: covalently bonded anions provide operating stability through suppressed oxygen loss, and the borate group (BO3) possesses the highest theoretical specific capacity for one-electron polyanion systems. In this work, we demonstrate an electrochemically superior lithium borate (LiMn0.5Fe0.4Mg0.1BO3) that delivers a near theoretical capacity (98%) of 201 mA h g-1 at C/50, an improved rate capability of 120 mA h g-1 at 1 C, and good capacity retention. Using ab initio modeling, the superior Li intercalation activity is explained by both stabilization of the delithiated state and increased topological cation disorder, which counter-intuitively facilitates Li transport. Our results indicate that through engineering of defect chemistry, the basic mechanism can be modified from one-dimensional to three-dimensional conduction, thereby improving kinetics. Combined with the inherent stability of the borate group, the enhanced electrochemical properties should reinvigorate search in borate chemistry for new safe and high-energy cathode materials.
AB - Simple borates are attractive cathodes for lithium-ion batteries due to two main reasons: covalently bonded anions provide operating stability through suppressed oxygen loss, and the borate group (BO3) possesses the highest theoretical specific capacity for one-electron polyanion systems. In this work, we demonstrate an electrochemically superior lithium borate (LiMn0.5Fe0.4Mg0.1BO3) that delivers a near theoretical capacity (98%) of 201 mA h g-1 at C/50, an improved rate capability of 120 mA h g-1 at 1 C, and good capacity retention. Using ab initio modeling, the superior Li intercalation activity is explained by both stabilization of the delithiated state and increased topological cation disorder, which counter-intuitively facilitates Li transport. Our results indicate that through engineering of defect chemistry, the basic mechanism can be modified from one-dimensional to three-dimensional conduction, thereby improving kinetics. Combined with the inherent stability of the borate group, the enhanced electrochemical properties should reinvigorate search in borate chemistry for new safe and high-energy cathode materials.
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U2 - 10.1039/c5ee00930h
DO - 10.1039/c5ee00930h
M3 - Article
AN - SCOPUS:84930718354
SN - 1754-5692
VL - 8
SP - 1790
EP - 1798
JO - Energy and Environmental Science
JF - Energy and Environmental Science
IS - 6
ER -