Low Temperature Electrolyte for High Capacity Lithium Based Batteries

A lithium based battery, comprising:

• a positive electrode comprising a lithium intercalation material,
• a negative electrode,
• a separator between the negative electrode and the positive electrode, and
• an electrolyte comprising LiPF6 and/or LiBF4, a solvent consisting of ethylene carbonate, dimethyl carbonate and ethylmethyl carbonate, and one or more lithium salt additives,
• wherein the battery has a specific capacity of at least about 80 mAh/g relative to the weight of the positive electrode active material when discharged at −30° C. from 4.5V to 2 V at a rate of C/10.

A lithium based battery comprising:

• a positive electrode comprising a lithium metal oxide approximately represented by the formula Li1+bNiαMnβCoγAδO2-zFz, where b ranges from about 0.01 to about 0.3, α ranges from about 0 to about 0.4, β range from about 0.2 to about 0.65, γ ranges from 0 to about 0.46, δ ranges from 0 to about 0.15 and z ranges from 0 to about 0.2 with the proviso that both α and γ are not zero, and where A is Mg, Sr, Ba, Cd, Zn, Al, Ga, B, Zr, Ti, Ca, Ce, Y, Nb, Cr, Fe, V, Li or combinations thereof.
• a negative electrode,
• a separator between the negative electrode and the positive electrode, and
• an electrolyte comprising from about 1.05M to about 2.0M of LiPF6 and/or LiBF4, and a solvent consisting of ethylene carbonate, dimethylcarbonate and ethylmethyl carbonate with a weight ratio of ethylene carbonate to dimethyl carbonate of 1:1 to 1:4 and ethylmethyl carbonate concentration is from about 5 weight percent to about 40 weight percent of the total weight of the electrolyte.

A lithium based battery comprising:

• a positive electrode comprising a lithium metal oxide having a specific discharge capacity of at least about 200 mAh/g at a rate of C/3 when discharged from 4.5V to 2V,
• a negative electrode,
• a separator between the negative electrode and the positive electrode, and
• an electrolyte comprising:
• from about 1.05M to about 2.0M LiPF6, LiBF4 or combinations thereof,
• a solvent consisting of fluoroethylene carbonate and dimethyl carbonate with a weight ratio of fluoroethylene carbonate to dimethyl carbonate of about 1:1 to about 1:4, and
• one or more lithium salt additives in a total amount from about 0.01 weight percent to about 10 weight percent of the total weight of the electrolyte,
• wherein the battery maintains at least 75% of its discharge energy density at the 2000th cycle at 1C charge and 2C discharge between 4.24V and 2.73V.