TY - JOUR
T1 - Highly concentrated carbonate electrolyte for Li-ion batteries with lithium metal and graphite anodes
AU - Xie, Jian De
AU - Patra, Jagabandhu
AU - Chandra Rath, Purna
AU - Liu, Weng Jing
AU - Su, Ching Yuan
AU - Lee, Sheng Wei
AU - Tseng, Chung Jen
AU - Gandomi, Yasser Ashraf
AU - Chang, Jeng Kuei
N1 - Publisher Copyright:
© 2019
PY - 2020/2/29
Y1 - 2020/2/29
N2 - Highly concentrated lithium bis(fluorosulfonyl)imide (LiFSI) salt dissolved in carbonate solvent is employed as a high-performance and robust organic electrolyte for Li-ion batteries. The influences of Li salt type, concentration, and solvent type (such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethylene carbonate (EC)) on the electrochemical properties of Li metal and graphite anodes are systematically assessed. A superior electrolyte composition of 5.5 M LiFSI-DMC/EC is achieved, enhancing the anti-flammability, coulombic efficiency, and high rate capability. The optimal efficiency values of Li electrodeposition/stripping utilizing 5.5 M LiFSI-DMC/EC are 97.0% and 94.5% at 0.4 and 6 mA cm−2, respectively. Such an enhanced performance is due to the formation of a three-dimensional ion network, composed of contact ion pairs (CIPs) and ion aggregates (AGGs) in the highly concentrated LiFSI electrolyte, which effectively decreases the number of free solvent molecules and inhibits the formation of undesired dendritic Li structures. Raman spectroscopy is employed to confirm the formation of CIP and AGG compounds within the electrolyte. The electrochemical data of the 5.5 M LiFSI-DMC/EC electrolyte cell demonstrates a remarkable improvement in the specific capacity and rate capability of a graphite anode.
AB - Highly concentrated lithium bis(fluorosulfonyl)imide (LiFSI) salt dissolved in carbonate solvent is employed as a high-performance and robust organic electrolyte for Li-ion batteries. The influences of Li salt type, concentration, and solvent type (such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethylene carbonate (EC)) on the electrochemical properties of Li metal and graphite anodes are systematically assessed. A superior electrolyte composition of 5.5 M LiFSI-DMC/EC is achieved, enhancing the anti-flammability, coulombic efficiency, and high rate capability. The optimal efficiency values of Li electrodeposition/stripping utilizing 5.5 M LiFSI-DMC/EC are 97.0% and 94.5% at 0.4 and 6 mA cm−2, respectively. Such an enhanced performance is due to the formation of a three-dimensional ion network, composed of contact ion pairs (CIPs) and ion aggregates (AGGs) in the highly concentrated LiFSI electrolyte, which effectively decreases the number of free solvent molecules and inhibits the formation of undesired dendritic Li structures. Raman spectroscopy is employed to confirm the formation of CIP and AGG compounds within the electrolyte. The electrochemical data of the 5.5 M LiFSI-DMC/EC electrolyte cell demonstrates a remarkable improvement in the specific capacity and rate capability of a graphite anode.
KW - Coulombic efficiency
KW - Dendritic Li structure
KW - Electrolyte composition
KW - Li battery
KW - Solid electrolyte interface
UR - http://www.scopus.com/inward/record.url?scp=85076669511&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2019.227657
DO - 10.1016/j.jpowsour.2019.227657
M3 - Article
AN - SCOPUS:85076669511
SN - 0378-7753
VL - 450
JO - Journal of Power Sources
JF - Journal of Power Sources
M1 - 227657
ER -