Enhanced LiMn_0.8Fe_0.2PO₄ Cathode Performance Enabled by the 1,3,2-Dioxathiolane-2,2-dioxide Electrolyte Additive

Abstract

Engineering the electrode/electrolyte interface through the addition of electrolyte additives has proven to be a promising strategy for enhancing the cell performance, and there are distinguishable discrepancies in the effect of 1,3,2-dioxathiolane-2,2-dioxide (DTD) as an electrolyte additive in different cell systems. Herein, DTD is added into the electrolyte for the Li/ LiMn 0.8 Fe 0.2 PO 4 cell and its functions on the LiMn 0.8 Fe 0.2 PO 4 cathode are studied. The result demonstrates that a beneficial effect on the LiMn 0.8 Fe 0.2 PO 4 performance is generated by adding DTD into the electrolyte, which is attributed to the decreased products arising from the interfacial side reactions on the surface of the LiMn 0.8 Fe 0.2 PO 4 cathode and the reduced metal dissolution in the electrolyte because of the easier and stronger binding between DTD and PF 6 − and the prioritized oxidation of DTD. The addition of DTD increased the capacity retention of the LiMn 0.8 Fe 0.2 PO 4 cathode from 46.52 to 70.54% after 1000 cycles at 1 C over the voltage range of 3.0−4.5 V. Therefore, DTD is rendered as an effective electrolyte additive for engineering the cathode/electrolyte interface in favor of enhancing the performance of LiMn 0.8 Fe 0.2 PO 4 , providing a facile interfacial strategy to enhance the performance of LiMnPO 4 -based cathodes.

Boron-Deficient Molecules Tailored Inorganic-rich Cathode/Electrolyte Interphaces for Stable Li||LiFe 0.2 Mn 0.8 PO 4 Battery

“…The impact of electrolyte additives on solid-electrolyte interphase (CEI) and battery performance has been well-demonstrated in the literature [13][14][15], including numerous boron-based compounds [16][17][18][19][20][21].…”