Influence of surface modification of LiCoO2 by organic compounds on electrochemical and thermal properties of Li/LiCoO2 rechargeable cells

LiCoO2 is the most famous positive electrode (cathode) for lithium ion cells. When LiCoO2 is charged at high charge voltages far from 4.2 V, cycleability of LiCoO2 becomes worse. Causes for this deterioration are instability of pure LiCoO2 crystalline structure and an oxidation of electrolyte solutions LiCoO2 at higher charge voltages. This electrolyte oxidation accompanies with the partial reduction of LiCoO2. We think more important factor is the oxidation of electrolyte solutions. In this work, influence of 10 organic compounds on electrochemical and thermal properties of LiCoO2 cells was examined as electrolyte additives.



J. Power Sources.  2011, 196: 2790–2801
http://dx.doi.org/10.1016/j.jpowsour.2010.11.064

A Guide to Li-Ion Coin-Cell Electrode Making for Academic Researchers

"To remain as relevant as possible, academic researchers need to be able to produce electrodes for lithium ion batteries that are comparable to those used in industry. This requires both a high percentage of active material and a high electrode density. Furthermore, the electrodes also need to adhere well enough to the current collecting foil to prevent particle detachment during cycling. While much of the knowledge needed to produce such electrodes is widely known in the industrial sphere, it is not readily available in the academic literature. Now that Li-ion battery technology has matured, reports of materials and cells tested using impractical electrodes are of limited value. This report outlines an effective method for producing high density, high capacity electrodes that have low amounts of binder and carbon black while still possessing excellent adhesion and electrochemical performance."

Journal of The Electrochemical Society. 2011, 158 (1 ), A51-A57

http://jes.ecsdl.org/content/158/1/A51.full.pdf+html

An example for ThTFA oxidation reaction

http://dx.doi.org/10.1016/j.jelechem.2007.11.034

Challenges Facing Lithium Batteries and Electrical Double-Layer Capacitors

http://onlinelibrary.wiley.com/store/10.1002/anie.201201429/asset/9994_ftp.pdf?v=1&t=h7kl03y6&s=31963e2a8782673a20be65d4d6991d07c262f719

Accessing the Synthetic Chemistry of Radical Ions

http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201101071/abstract

Organic reactions involving radical cation and radical anion intermediates are synthetically powerful umpolung processes that enable electronically mismatched couplings between pairs of electron-rich or pairs of electron-poor organic fragments. Nevertheless, the adoption of these reactions as synthetic methods has been relatively slow in comparison with that of reactions involving more conventional reactive intermediates such as carbanions, carbocations, and neutral radicals. This Microreview provides a brief survey of radical ion chemistry and highlights the use of transition metal photocatalysis as a convenient means to investigate radical-ion-mediated transformations.

Applications of Metallocenes in Rechargeable Lithium Batteries for Overcharge Protection

http://jes.ecsdl.org/content/139/1/5

One problem encountered in the development of rechargeable lithium batteries is the protection of individual cells from overcharging. In this work the addition of metallocene derivatives to cell electrolytes to provide overcharge protection was investigated. Eleven ferrocene derivatives were studied in terms of their redox potentials and mass transport properties in electrochemical cells and “AA”‐size  rechargeable cells employing  in 50/50 volume percent propylene carbonate/ethylene carbonate (PC/EC) as the electrolyte. The chemical and electrochemical properties of these metallocene derivatives were also studied in terms of the chemical stability of the derivatives toward cell components and electrochemical reversibility in long‐term cycling studies. It was found that adsorption of one derivative, dimethylaminomethylferrocene, on the  electrode ( based on the Langmuir adsorption isotherm), blocked the intercalation of Li⁺ ions into the  electrode.

n‐Butylferrocene for Overcharge Protection of Secondary Lithium Batteries

http://jes.ecsdl.org/content/137/6/1856