Electrochemical Property Enhancement of LiNi_0.5Mn_1.5O₄ Cathodes at High Temperatures Using 1,1,3,3-Tetramethyldisiloxane

In this work, we propose that 1,1,3,3-tetramethyldisiloxane (TMDS) is beneficial for electrochemical property enhancement of LiNi0.5Mn1.5O4/Li cells at high temperatures. The LiNi0.5Mn1.5O4/Li cells with 1 vol % TMDS revealed capacity retention of 81.2% after a cycling test at 55 °C, while the cells without additive showed capacity retention of only 32.3%. The cells with 1 vol % TMDS also presented a better rate performance, reaching 100 mAh g–1 under 3C. Physical characterization and theoretical calculations revealed that TMDS formed a thinner and better conductive layer on the LiNi0.5Mn1.5O4 surface and effectively scavenged HF/F– from the electrolyte, contributing to high stabilization of LiNi0.5Mn1.5O4.