Patent ID: 6114069
Filing Date: 2000-09-05
Classification: H01M,Y02E

Abstract:
Rechargeable lithium battery comprising at least one lithium anode, one lithium ion reducible cathode bonded to a first polymer, and a polymer electrolyte comprising a lithium salt in solution in a second polymer, said lithium battery containing an additive comprising potassium ions introduced in the form of potassium salts selected from the group consisting of KN(R.sub.F SO.sub.2).sub.2, KN(FSO.sub.2).sub.2, K(FSO.sub.2 --N--SO.sub.2 R.sub.F) and KR.sub.F SO.sub.3 in which R.sub.F represents a perhalogenoalkyl, perhalogenooxyalkyl, perhalogenothiaalkyl or perhalogenoaryl group optionally containing aza or oxa substituents, and the two R.sub.F groups in the KN(R.sub.F SO.sub.2).sub.2 are identical or different or form together a perhalogenated ring having 1 to 6 carbon atoms and optionally containing in the ring at least one oxygen or nitrogen atom, said potassium ions being distributed in at least one of said cathode and said polymer electrolyte, the concentration of lithium and potassium in the second polymer when said battery has reached equilibrium, expressed as O/(Li+K), being between about 8/1 and 40/1 while the molar ratio Li/K is between about 0.2 to 15, said potassium ions being selected so as to stabilize performances of the battery during cycling in terms of energy and power.