High-Precision Differential Capacity Analysis of LiMn2O4/graphite Cells

Abstract

The differential capacity and charge–discharge end points of a commercial LiMn2O4/graphite cell were examined using high precision constant-current chronopotentiometry and coulometry. The positive and negative electrodes from a fresh commercial cell were recovered and used to generate high precision "reference" potential-capacity data versus Li. The reference data were used to calculate differential capacity versus potential for "theoretical" LiMn2O4/graphite cells which could be perfectly matched to data from experiments on full cells. Matching was achieved primarily by relative "slippage" in capacity of the positive and negative potential-capacity curves. This allowed a detailed understanding of the aging processes and capacity fade of a full cell.