Preparation of LiBOB via rheological phase method and its application to mitigate voltage fade of Li1.16[Mn0.75Ni0.25]0.84O2 cathode
发表时间：2015-12-24 13:03
Lithium bis(oxalato)borate (LiBOB) was synthesized via a novel rheological phase reaction method without
any recrystallization procedure. The purity of the as-obtained LiBOB has been identified in comparison with
the commercial sample and our sample prepared from solid-state reaction method. The results of XRD, ICP,
and 11B NMR demonstrate that high pure LiBOB has been synthesized via rheological phase reaction
method with significantly simplified synthetic process. Moreover, LiBOB sample has been investigated as
electrolyte additive to improve the electrochemical performances of high-energy lithium-rich layered
oxide. The cycling performances imply that 0.03 M and 0.05 M LiBOB additive can mitigate discharge
voltage fade and enhance the cycle stability of Li1.16[Mn0.75Ni0.25]0.84O2 material. The CV, EIS and XPS
data indicate that LiBOB oxidizes at 4.3 V (vs. Li/Li+) on the cathode surface during the first charge to
form a specific SEI layer with larger amount of organic species and fairly less content of LiF, which
decreases the interfacial polarization and protects the active material from surface degradation, thereby
mitigates the voltage-fade of Li-rich cathode.