Patent ID: 7749288

Claim:
A method of manufacturing a lithium electrochemical cell containing less than 1500 ppm by weight of sodium, the method comprising (a) providing a cathode comprising a cathode active material including iron disulfide that has been treated with a neutralizing agent that includes lithium but not sodium, an anode, a separator, and an electrolyte comprising a first ether and a lithium salt, wherein the neutralizing agent includes lithium hydroxide, and wherein the first ether is dimethoxyethane, these components having sufficiently low quantities of sodium that, when combined with a case, can provide a lithium electrochemical cell containing less than 1500 ppm by weight of sodium, and (b) assembling the cathode, the anode, the separator, and the electrolyte from step (a) into the case to provide a lithium electrochemical cell containing less than 1500 ppm by weight of sodium.