Improving the Cyclic Stability of LiNi_0.5Mn_1.5O₄ at High Cutoff Voltage by Using Pyrene as a Novel Additive

Abstract

Pyrene (PY) is first used as an additive to improve the cyclic stability of LiNi0.5Mn1.5O4 at high cutoff voltage. After 300 cycles at room temperature (≈25 °C) and 100 cycles at elevated temperature (≈55 °C), the capacity retention of Li/LiNi0.5Mn1.5O4 cells is 93.1% and 92.68% in the electrolyte containing 0.0025 wt% PY. However, in the base electrolyte, the capacity retention of the cells is 84.7% and 88.12%. The improved capacity retention is due to a thin and even cathode electrolyte interphase (CEI) film containing the poly‐PY on surface of LiNi0.5Mn1.5O4, which reduces the oxidation reaction of electrolyte, the dissolution of transition metal, and the interface impedance in subsequent cycles. In addition, the cross‐talk effect between the positive and negative electrodes is effectively avoided. The film derived from PY also improves the rate performance of cell at room temperature.

Cobalt‐Free Cathode Materials: Families and their Prospects

“…[ 254 ] As a possible solution, an optimized electrolyte composition can improve long‐term cycling performance either by removing a certain amount of undesirable water or HF or by lessening TM dissolution from the cathode. [ 201 ] As reported by Shang et al., [ 255 ] the addition of pyrene can improve the high‐voltage charging performance of LNMO, which maintains its cell capacity for at least 300 cycles at ambient temperature. Additionally, when the temperature increases (≈55 °C), 92.68% of the initial capacity is maintained after 100 cycles in the LNMO/Li configuration, which performs better than those using an ordinary electrolyte (88.12%).…”

Crucial interactions of functional pyrenes with graphite in electrodes for lithium‐ion batteries

“…The non-covalent attachment of pyrenes to carbon surfaces has already led to great success concerning the dispersion of nanotubes [8][9][10] and conductivity tuning of graphene. [10,11] The use of pyrenes as electrolyte additive, [12] stabilizer of carbon nanotubes components, [13] surface modifiers for graphite felts, [14] or part of polymeric active materials [15][16][17] in energy storage systems has also been reported.…”