Influence of PESU/PVP based nanofibrous separators on the properties of LNMO cathode based Li-ion batteries

Abstract

The properties of selected separators and their influence on the electrochemical properties of a high-voltage cathode material are investigated in this paper. The LiCr_0.1Ni_0.4Mn_1.5O₄ material synthesized by a solid-state reaction was chosen as the testing material. Four kinds of separators were selected for this study, including a glass fiber separator, a commercial separator made by Celgard and experimental separators made by the Nafigate Corporation. The main goal was to study the properties of the commercial and non-commercial separators and their influence on reached capacity, stability during cycling at high loads and stability during cycling at high temperatures. It was observed that the Nafigate separators are more thermally stable with lower shrinking up to 150 °C and exhibit comparable conductivity to the Celgard separator. In combination with the LiCr_0.1Ni_0.4Mn_1.5O₄ cathode, the Nafigate separator also achieves higher capacity at lower C-rate (0.5C ∼130 mAh g⁻¹) and at higher load (5C) it reaches ∼111 mAh g⁻¹. The Celgard separator reaches a capacity of ∼118 mAh g⁻¹ at 0.5C and ∼83 mAh g⁻¹ at higher load (5C).