Suppression of an Alkyl Dicarbonate Formation in Li-Ion Cells

Two methods were developed to suppress the formation of alkyl dicarbonate in Li-ion cells. One is the addition of vinylene carbonate (VC), which is vulnerable to nucleophilic attack, into the electrolyte to trap alkoxide anions that promote an alkyl dicarbonate formation. The addition of VC into the electrolyte of practical graphite/LiCoO 2 prismatic cells effectively suppressed an alkyl dicarbonate formation and gave better cycle and power performance. The other method is a surface treatment of graphite to reduce the concentration of phenolic groups that were directly bonded to the graphite edge plane. The mild burn-off treatment successfully decreased the oxygen concentration on graphite surface and effectively suppressed an alkyl dicarbonate formation in the electrolyte. However, the irreversible capacity increased significantly, which was considered to be due to a change in the surface morphology of graphite by the burn-off treatment.

[1]  F. Bovey.  The high resolution NMR spectroscopy of polymers , 1971 .

[2]  Y. Rosenberg,et al.  Characterization of modified NG7 graphite as an improved anode for lithium-ion batteries , 1997 .

[3]  Kimihito Suzuki,et al.  Effect of Graphite Surface Structure on Initial Irreversible Reaction in Graphite Anodes , 1999 .

[4]  Shoji Yamaguchi,et al.  Analysis of Vinylene Carbonate Derived SEI Layers on Graphite Anode , 2004 .

[5]  J. Besenhard,et al.  Modified carbons for improved anodes in lithium ion cells , 2001 .

[6]  T. Abe,et al.  Effect of an Alkyl Dicarbonate on Li-Ion Cell Performance , 2005 .

[7]  J. Besenhard,et al.  Surface modification of graphite anodes by combination of high temperature gas treatment and silylation in nonaqueous solution , 2001 .

[8]  T. Takamura,et al.  Surface modification of pitch-based carbon fibre for the improvement of electrochemical lithium intercalation , 1995 .

[9]  R. Leising,et al.  Novel Impact of Short Term Aging on the Electrochemistry of CO 2 Treated Synthetic Graphite , 2004 .

[10]  Hong Gan,et al.  Anode Passivation and Electrolyte Solvent Disproportionation: Mechanism of Ester Exchange Reaction in Lithium‐Ion Batteries , 1997 .

[11]  Minoru Inaba,et al.  Effects of Some Organic Additives on Lithium Deposition in Propylene Carbonate , 2002 .

[12]  D. Aurbach,et al.  On the use of vinylene carbonate (VC) as an additive to electrolyte solutions for Li-ion batteries , 2002 .

[13]  E. Peled,et al.  A Study of Highly Oriented Pyrolytic Graphite as a Model for the Graphite Anode in Li‐Ion Batteries , 1999 .

[14]  E. Peled,et al.  Improved Graphite Anode for Lithium‐Ion Batteries Chemically Bonded Solid Electrolyte Interface and Nanochannel Formation , 1996 .

[15]  T. Abe,et al.  Surface Film Formation on a Graphite Negative Electrode in Lithium-Ion Batteries: Atomic Force Microscopy Study on the Effects of Film-Forming Additives in Propylene Carbonate Solutions , 2001 .