3-(1,1,2,2-Tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane as a High Voltage Solvent for LiNi_1/3Co_1/3Mn_1/3O₂/Graphite Cells

Abstract

A new electrolyte based on fluorinated 3-(1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane (F-EPE) solvent is developed to decrease the capacity fading of LiNi 1/3 Co 1/3 Mn 1/3 O 2 /graphite lithium-ion batteries (LIBs) cycled in the voltage range of 3.0-4.5 V (vs. Li/Li + ). The linear sweep voltammetry (LSV) and cyclic voltammetry (CV) indicate that F-EPE has an oxidation potential of more than 5.4 V vs. Li/Li + , which is higher than traditional solvents and enlarges the oxidative window of electrolyte. Especially, compared with the LiNi 1/3 Co 1/3 Mn 1/3 O 2 /graphite cells without F-EPE in the electrolyte, the capacity retentions of the cells contained 20 wt% F-EPE and cycled in 3.0-4.5 V are significantly increased from 12.3% to 85.0% after 100 cycles. In addition, the cathode and the anode are respectively characterized in three-electrode systems by electrochemical impedance spectrum (EIS), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and transmission electron microscopy (TEM) to elaborate the reaction mechanism of F-EPE in the cells. The enhanced performances can be ascribed to that F-EPE cannot only greatly improve the oxidation stability of electrolyte solutions but also participate in the formation of passivation film on the graphite anode, indicating the positive effect of F-EPE on the performances of LIBs cycled in 3.0-4.5 V.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 10.220.39.223 Downloaded on 2015-07-27 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 10.220.39.223 Downloaded on 2015-07-27 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 10.220.39.223 Downloaded on 2015-07-27 to IP

Electrolyte Solutions for Rechargeable Li-Ion Batteries Based on Fluorinated Solvents

“…38 Zhang et al 3 LiNi 1/3 Co 1/3 Mn 1/3 O 2 /graphite electrodes cycled in a voltage range of 3.0−4.5 V (vs. Li/Li + ). 39 Luo et al applied F-EPE for improved cycling of cells containing high-voltage cathodes LiNi 0.5 Mn 1.5 O 4 . 40 The stability and performance of these electrolyte solutions may also depend on the presence of various impurities.…”

“…It was found that the electrolyte solutions containing fluorinated carbonates and F-EPE ether have superior electrochemical stability compared with the EC/EMC-based electrolyte solutions. Wang et al utilized F-EPE to improve the cycling stability of full cells based on LiNi 1/3 Co 1/3 Mn 1/3 O 2 /graphite electrodes cycled in a voltage range of 3.0–4.5 V (vs. Li/Li + ) . Luo et al applied F-EPE for improved cycling of cells containing high-voltage cathodes LiNi 0.5 Mn 1.5 O 4 …”

LiNixCoyMnzO2 cathode materials for lithium (-ion) batteries

“…Even at higher C-rates, the cell still achieved a capacity of 142.0, 132.0, 114.4 mAh g -1 at 1 C, 2 C and 5 C (Figure 6.4d), respectively. These values compete well with those already reported in literature for lithium-ion batteries with advanced configuration[262,263], due to the high C-rate performance of MP-NCM.Figure 6.4e reveals the cycling performance of the full cell. After initial few cycles at 0.1 C for activation, the cell was cycled at 1 C with 147.5 mAh g -1 of capacity delivered.…”

Improved electrochemical performance of a LiCoO2/MCMB cell by regulating fluorinated electrolytes

“…4a–d ), a pair of clear redox peak stands for Li + extraction/insertion in the MCMB. 29 A weak reduction peak located at 1.1–1.2 V ( Fig. 4b and d ) should be attributed to participation of SEI construction by fluorinated ether TFEE.…”