摘要
Lithium-ion batteries(LIBs)with ether-based electrolytes usually provide low cell performance when matched with the graphite(Gr)anodes due to cointercalation of Li+-solvent.Herein,a novel deep eutectic ether electrolyte with polyethylene glycol dimethyl ether(PEGDME)featuring low flammability and high safety is developed,and fluoroethylene carbonate(FEC)is adopted to mitigate the cointercalation phenomenon.Unlike the common effect of FEC’s role in the first solvation shell,our results reveal that FEC molecules affect the Li+-PEGDME insertion behavior through FECPEGDME intramolecular interaction.As a result,a high discharge capacity of 450 mA h g^(−1)is achieved in Li||Gr/SiO_(x)cells at 50℃,and 370 mA h g^(−1)can be realized,even at−20℃(three times higher than commercial carbonate electrolyte).Moreover,Gr/SiO_(x)||LiNi_(0.6)Co_(0.2)Mn_(0.2O2)full cells maintain good capacity retention in both coin cell and pouch cell configurations over a wide temperature range.Our work deciphers the role of FEC as an additive and proposes new electrolyte optimization strategies to achieve high-performance all-climate LIBs.
基金
supported by the Jilin Province Science and Technology Department Major Science and Technology Project(grant nos.20220301004GX and 20220301005GX)
Key Subject Construction of Physical Chemistry of Northeast Normal University
and the National Natural Science Foundation of China(grant nos.22102020 and 22279014).
