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

Electrochemical Characterization of SEI-Type Passivating Films Using Redox Shuttles

http://jes.ecsdl.org/content/159/7/A1057.full.pdf+html?sid=f006219b-2c67-4fed-94d0-99ad7757ade6

substituents on ferrocene and Hammet coefficients

In situUV–visible spectroscopy: characterization of overcharge protection additives for secondary lithiumbatteries

http://www.sciencedirect.com/science/article/pii/S0378775399001792

In situ spectroscopic investigation of the anodic oxidation of 1,4-dimethoxybenzene at platinum electrodes

http://www.sciencedirect.com/science/article/pii/S0379677997038277

Surface Modification Patent - Stephen!

http://www.google.com/patents?id=6AgSAgAAEBAJ&pg=PA1&lpg=PA1&dq=khalil+amine&source=bl&ots=2bneVum69x&sig=77NOtn3gpnSpQqJqaGIHO3ZPqnU&hl=en&sa=X&ei=WWc_UI2aAefU2AWzuIHIDA&ved=0CC8Q6AEwAA#v=onepage&q=khalil%20amine&f=false

Polymerizable Additives as Redox Shuttles - Patent

http://www.google.com/patents?id=0WMWAAAAEBAJ&printsec=frontcover&dq=Redox+shuttles+for+high+voltage+cathodes&source=bl&ots=EK2uvNZGit&sig=mShPdCAdWb7aVcrylImgajejCas&hl=en&sa=X&ei=92Y_UI2hCqbe2AWWvICoDQ&ved=0CDcQ6AEwAzgU

2. A non-aqueous rechargeable lithium battery as claimed in claim 1 wherein the monomer additive comprises less than about 5% by volume of the mixture of liquid electrolyte and monomer.

3. A non-aqueous rechargeable lithium ion battery having a maximum operating charging voltage and overcharge protection comprising:

a lithium insertion compound cathode;

a lithium insertion compound anode;

a separator;

a non-aqueous liquid electrolyte incapable of polymerizing at voltages greater than the maximum operating voltage of the lithium ion battery such that the battery is protected during overcharge abuse; and

an aromatic additive mixed in said liquid electrolyte, said additive polymerizing at battery voltages greater than the maximum operating voltage thereby increasing the internal resistance of the lithium ion battery and protecting the battery during overcharge abuse.

Dahn's thianthrene redox shuttle

http://www.google.com/patents?id=qZQXAAAAEBAJ&printsec=frontcover&dq=Redox+shuttles+for+high+voltage+cathodes&source=bl&ots=pTckq6ntnI&sig=0-tTKcgF0J-o3qjM8s39TeEinm0&hl=en&sa=X&ei=2GQ_UMrOGoeq2gX6i4G4DQ&ved=0CEoQ6AEwCQ

18. A method for providing a rechargeable, electrochemical cell, comprising the steps of

providing an anode and a cathode,

providing an electrolyte in contact with said anode and said cathode; and

dissolving within said electrolyte a thianthrene based compound for acting as a redox shuttle reagent to provide overcharge protection to the cell.

19. A method for providing a rechargeable, electrochemical cell according to claim 18 wherein the step of providing an electrolyte includes the step of providing a Li salt dissolved in an organic solvent or a solvent mixture selected from ethers, carbonates esters, sulfones, ketones and lactones.

20. A method for providing a rechargeable, electrochemical cell according to claim 18 wherein the step of providing an electrolyte includes the step of providing a polymer electrolyte comprised of a Li salt, a polymer host and a plasticizer solvent.

21. A method for providing a rechargeable, electrochemical cell according to claim 18 wherein the step of providing a thianthrene containing compound includes the step of providing 2,7-diacetyl thianthrene.

Dahn's patent on fluorinated alkoxybenzene derivatives

http://www.google.com/patents?id=1RYCAgAAEBAJ&printsec=frontcover&dq=Redox+shuttles+for+high+voltage+cathodes&source=bl&ots=3pTaki2M4H&sig=S66F-BlIKxrSvwxEBAlllbaCaFs&hl=en&sa=X&ei=G2Y_UOSwLcm42wXv3IHIDQ&ved=0CC8Q6AEwAA

1. A rechargeable electrochemical cell comprising:

a positive electrode having at least one electroactive material having a recharged potential;

a negative electrode;

a charge-carrying electrolyte comprising a charge carrying medium and an electrolyte salt; and

a cyclable redox chemical shuttle comprising an aromatic compound substituted with at least one tertiary alkyl group and at least one halogenated alkoxy group, dissolved in or dissolvable in the electrolyte and having an oxidation potential above the recharged potential of at least one of the electroactive materials of the positive electrode principal electroactive material.

2. The cell according to claim 1, wherein at least one alkoxy group comprises a fluorinated alkoxy group.

3. The cell according to claim 2, wherein the partially fluorinated alkoxy group comprises from one to about four carbon atoms.

4. The cell according to claim 3, wherein the partially fluorinated alkoxy group(s) are selected from —OCH2F, —OCH2CF3, —OCH2CF2CF3, —OCH2CF2CF2CF3, —OCH2CF2CF2H and —OCH2CF2CFHCF3.

5. The cell according to claim 1, wherein the aromatic compound is substituted with at least two tertiary alkyl groups and at least two halogenated alkoxy groups.

6. The cell according to claim 1, wherein at least one tertiary alkyl group comprises a butyl group.

7. The cell according to claim 1, wherein the shuttle comprises a compound having the formula:

wherein R1 and R2 can each, independently, be H or a tertiary alkyl group with four to twelve carbon atoms, wherein at least one of R1 or R2 is a tertiary alkyl group, wherein each Rf can, independently, be H or a halogenated alkoxy group having the formula —OR′ where R′ is a halogenated alkyl group having up to 10 carbon atoms, and wherein at least one Rf is a halogenated alkoxy group.

Amine's patent on phosphonate redox shuttles

http://www.google.com/patents?id=Auv-AQAAEBAJ&pg=PA11&lpg=PA11&dq=Redox+shuttles+for+high+voltage+cathodes&source=bl&ots=wVbU5r1XK4&sig=2DusT_PibwmwGfJZWRq9q3t438U&hl=en&sa=X&ei=2GQ_UMrOGoeq2gX6i4G4DQ&ved=0CDIQ6AEwAQ#v=onepage&q=Redox%20shuttles%20for%20high%20voltage%20cathodes&f=false

Dahn's 2,5-di-tert-butyl-1,4-dimethoxybenzene patent

http://www.google.com/patents?id=EYaVAAAAEBAJ&printsec=frontcover&dq=Redox+shuttles+for+high+voltage+cathodes&source=bl&ots=eMYfFrnM5a&sig=wd70Otm0sspe242rxxr24UG9Zhw&hl=en&sa=X&ei=2GQ_UMrOGoeq2gX6i4G4DQ&ved=0CDsQ6AEwBA

1. A lithium ion cell electrolyte comprising a charge carrying medium, lithium salt and cyclable redox chemical shuttle comprising an aromatic compound substituted with at least one tertiary carbon organic group and at least one alkoxy group.
2. An electrolyte according to claim 1 wherein the charge carrying medium comprises ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, dimethoxyethane or combination thereof and the lithium salt comprises LiPF6, lithium bis(oxalato)borate or combination thereof.
3. An electrolyte according to claim 1 wherein the aromatic compound has a single organic ring.
4. An electrolyte according to claim 1 wherein the aromatic compound is substituted with two tertiary carbon groups, each tertiary carbon group independently having up to 12 carbon atoms.
5. An electrolyte according to claim 1 wherein the tertiary carbon group is tert-butyl.
6. An electrolyte according to claim 1 wherein the aromatic compound is substituted with two alkoxy groups, each alkoxy group independently having up to 10 carbon atoms.
7. An electrolyte according to claim 1 wherein the aromatic compound comprises 2,5-di-tert-butyl- 1 ,4-dimethoxybenzene.

Dahn's Phenothiazine Patent

http://www.google.com/patents?id=ftiZAAAAEBAJ&printsec=frontcover&dq=Redox+shuttles+for+high+voltage+cathodes&source=bl&ots=V318sPtkA3&sig=VypaNE89_PbRaUxiHHRS2bF1nqA&hl=en&sa=X&ei=2GQ_UMrOGoeq2gX6i4G4DQ&ved=0CDgQ6AEwAw

A cell according to claim 1 wherein the phenothiazine compound is substituted with one or more acyl, acyloxy, alkaryl, alkoxy, acetamido, amido, amino, aryl, aralkyl, alkyl carboxyl, aryl carboxyl, alkylsulfonyl, benzoyl, carbamoyl, carbamido, carboxy, cyano, formyl, halo, haloacetamido, haloacyl, haloalkylsulfonyl, haloaryl, hydroxyl, isothiocyanato, methylsulfonyloxyl, nitro, oxo, oxybenzoyl or phosphenoxy groups or combination thereof.

A cell according to claim 1 wherein the phenothiazine compound comprises 10-methyl-phenothiazine, 10-ethyl-phenothiazine, 3-chloro-10-ethyl-phenothiazine, 10-isopropyl-phenothiazine or 10-acetyl-phenothiazine or mixture thereof.

A cell according to claim 1 wherein the phenothiazine compound comprises 2-perfluoromethyl-phenothiazine, 2-chloro-10-methyl-phenothiazine, 2-ethyl-10-methyl-phenothiazine, 3-bromo-10-ethyl-phenothiazine, 3-chloro-10-methyl-phenothiazine, 3-iodo-10-methyl-phenothiazine, 10-methyl-phenothiazin-3-ol, 10-methyl-phenothiazin-3-ylamine, 2,10-dimethyl-phenothiazine, 3,10-dimethyl-phenothiazine, 3-methyl-10-ethyl-phenothiazine, 4,10-dimethyl-phenothiazine, 3,7,10-trimethyl-phenothiazine, 10-(2-chloroethyl)-phenothiazine, 10-formyl-phenothiazine, 10-methoxy-phenothiazine, 10-methoxymethyl-phenothiazine, 10-phenyl-phenothiazine, 10-propionyl-phenothiazine, 10-methyl-phenothiazine-4-carboxylic acid or mixture thereof.

A cell according to claim 1 wherein the phenothiazine compound comprises 2-cyano-10-perfluoromethylsulfonyl-phenothiazine, 2-methoxy-10-perfluoromethylsulfonyl-phenothiazine, 2-perfluoromethyl-10-perfluoromethylsulfonyl-phenothiazine, 10-perfluoromethyl-phenothiazine, 10-perfluoromethylsulfonyl-phenothiazine, 10-(1,1,1,2,3,3)-hexafluoropropyl-phenothiazine or mixture thereof.

BCN-BuPT

http://www.ingentaconnect.com/content/ben/loc/2012/00000009/00000003/art00011?token=00581c08a96421bbf79c6e58654624317b42316b74217e662a77535e4e2663433b393f6a333f256681955087

and

http://www.sciencedirect.com/science/article/pii/S0040403908005236

monoCN-EPT procedure

http://pubs.acs.org/doi/abs/10.1021/la8027226?source=chemport

dibromo-N-ethylphenothiazine crystal structure

http://journals.iucr.org/c/issues/1986/12/00/a26259/a26259.pdf