Ultrafast anode for high voltage aqueous Li-ion batteries

作者：Levi M D^*; Shilina Yu; Salitra G; Aurbach D; Guyot E; Seghir S; Lecuire J M; Boulanger C

来源：Journal of Solid State Electrochemistry, 2012, 16(11): 3443-3448.

DOI：10.1007/s10008-012-1841-1

• Aqueous Li-ion batteries
• Ultrafast anode
• Chevrel phase
• High rate capability
• LixMn2O4 spinel cathode
• Self-discharge

Clustered Mo sulfide Mo6S8 (Chevrel phase) demonstrates outstandingly high rate capability in contact with concentrated aqueous Li2SO4 solutions. Slow galvanostatic cycling can be performed with good Faradaic efficiency at a moderate capacity of 32.1 mAhg(-) (1) (1e(-) reduction of Mo6S8), which in combination with 1e(-) oxidation process in Li (x) Mn2O4 cathode, results in equilibrium cell voltage of 1.5 V. Higher rates of charge and discharge have been also achieved within a considerably extended apparent electrochemical stability window involving second two-electron reduction of Mo6S8 which leads to apparent cell voltage of 1.85 V, specific capacity about 74.7 mAhg(-1) at 90 % Faradaic efficiency, specific energy of 74 Wh kg(-1) (related to both electrodes) at extremely high charge-discharge rate of 60 C. Our study highlights the generic feature of Li-ion aqueous cells, namely, a high rate capability coupled with a relatively fast self-discharge which necessitates a more profound understanding of the nature of self-discharge in Li-ion insertion hosts in contact with aqueous solutions.

• 出版日期2012-11