Thermal Decomposition Study on Li 2 O 2 for Li 2 NiO 2 Synthesis as a Sacrificing Positive Additive of Lithium-Ion Batteries

Molecules. 2019 Dec 17;24(24):4624. doi: 10.3390/molecules24244624.

Abstract

Herein, thermal decomposition experiments of lithium peroxide (Li2O2) were performed to prepare a precursor (Li2O) for sacrificing cathode material, Li2NiO2. The Li2O2 was prepared by a hydrometallurgical reaction between LiOH·H2O and H2O2. The overall reaction during annealing was found to involve the following three steps: (1) dehydration of LiOH·H2O, (2) decomposition of Li2O2, and (3) pyrolysis of the remaining anhydrous LiOH. This stepwise reaction was elucidated by thermal gravimetric and quantitative X-ray diffraction analyses. Furthermore, over-lithiated lithium nickel oxide (Li2NiO2) using our lithium precursor was synthesized, which exhibited a larger yield of 90.9% and higher irreversible capacity of 261 to 265 mAh g-1 than the sample prepared by commercially purchased Li2O (45.6% and 177 to 185 mAh g-1, respectively) due to optimal powder preparation conditions.

Keywords: Li source; Li-ion battery; Li2NiO2; Li2O; Li2O2; thermal decomposition.

MeSH terms

  • Electric Power Supplies*
  • Ions / chemistry*
  • Lithium / chemistry*
  • Nickel / chemistry*
  • X-Ray Diffraction

Substances

  • Ions
  • Nickel
  • Lithium
  • nickel monoxide