Auxiliary electrode for lithium-ion battery

Abstract

An auxiliary electrode for a lithium-ion battery includes a lithium source material. The auxiliary electrode is configured to selectively couple to a negative electrode of a lithium-ion battery to provide lithium for formation of a solid-electrolyte-inter-phase layer on a negative electrode.

What is claimed is: 
     
         1 . An auxiliary electrode for a lithium-ion battery, the auxiliary electrode comprising:
 a lithium source material;   wherein the auxiliary electrode is configured to selectively couple to a negative electrode of a lithium-ion battery to provide lithium for formation of a solid-electrolyte-inter-phase layer.   
     
     
         2 . The auxiliary electrode of  claim 1 , wherein the auxiliary electrode is configured to selectively couple to a negative electrode during a formation process of a battery. 
     
     
         3 . The auxiliary electrode of  claim 2 , wherein the auxiliary electrode is configured to selectively couple to a negative electrode after a charging process of a battery. 
     
     
         4 . The auxiliary electrode of  claim 1 , wherein the auxiliary electrode is configured to selectively couple to a negative electrode after a discharge of a battery. 
     
     
         5 . The auxiliary electrode of  claim 1 , wherein the auxiliary electrode is a lithium patch. 
     
     
         6 . The auxiliary electrode of  claim 1 , wherein the lithium source material has a potential versus Li/Li +  that is greater than a potential versus Li/Li +  of an active material of a negative electrode. 
     
     
         7 . The auxiliary electrode of  claim 1 , wherein the lithium source material has a potential versus Li/Li +  that is less than a potential versus Li/Li +  of an active material of a negative electrode. 
     
     
         8 . A lithium-ion battery comprising:
 a negative electrode;   a positive electrode; and   an auxiliary electrode;   wherein the auxiliary electrode includes a lithium source material, and the auxiliary electrode is configured to selectively couple to the negative electrode to provide lithium for formation of a solid-electrolyte-inter-phase layer on the negative electrode.   
     
     
         9 . The lithium-ion battery of  claim 8  wherein lithium may travel from the auxiliary electrode to the negative electrode through an electrolyte. 
     
     
         10 . The lithium-ion battery of  claim 9  further comprising a case, wherein the negative electrode, the auxiliary electrode, and the electrolyte are disposed within the case. 
     
     
         11 . The lithium-ion battery of  claim 9  wherein the negative electrode and at least a first portion of the electrolyte are disposed within a first case, the auxiliary electrode and a second portion of the electrolyte are disposed within a second case, and the first case and second case are in fluid communication by a pass-through, such that lithium may travel from the auxiliary electrode through the electrolyte to the negative electrode. 
     
     
         12 . The lithium-ion battery of  claim 8 , wherein the lithium source material has a potential versus Li/Li +  that is less than a potential versus Li/Li +  of an active material of the negative electrode. 
     
     
         13 . The lithium-ion battery of  claim 8 , wherein the lithium source material has a potential versus Li/Li +  that is greater than a potential versus Li/Li +  of an active material of a negative electrode. 
     
     
         14 . The lithium-ion battery of  claim 8 , wherein a circuit having a switch extends from the auxiliary electrode to the negative electrode, and wherein the auxiliary electrode is selectively coupled to the negative electrode by closing the switch. 
     
     
         15 . The lithium-ion battery of  claim 14  further comprising a case, wherein the auxiliary electrode, the negative electrode, and the switch are disposed inside the case. 
     
     
         16 . The lithium-ion battery of  claim 15 , wherein the circuit includes a resistance. 
     
     
         17 . The lithium-ion battery of  claim 14 , wherein the circuit includes a voltage source. 
     
     
         18 . The lithium-ion battery of  claim 17  further comprising a case, wherein the auxiliary electrode, the negative electrode, the switch, and the voltage source are disposed outside the case. 
     
     
         19 . The lithium-ion battery of  claim 8 , wherein the auxiliary electrode is configured to selectively couple to the negative electrode during a formation process of the battery. 
     
     
         20 . The lithium-ion battery of  claim 19 , wherein the auxiliary electrode is coupled to the negative electrode after an initial charging process of the battery, and wherein the electrode is coupled to the negative electrode with a circuit having a voltage source and a resistance. 
     
     
         21 . The lithium-ion battery of  claim 8 , wherein the auxiliary electrode is configured to selectively couple to the negative electrode after a discharge of the battery. 
     
     
         22 . The lithium-ion battery of  claim 21 , wherein the auxiliary electrode is configured to selectively couple to the negative electrode with a circuit having a resistance. 
     
     
         23 . The lithium-ion battery of  claim 22 , wherein the circuit includes a voltage source. 
     
     
         24 . A method for forming a solid electrolyte interface in a lithium-ion battery comprising:
 providing a lithium-ion battery having a positive electrode, a negative electrode, and an auxiliary electrode having a lithium source material, the electrodes being in contact with a common electrolyte;   charging the battery by coupling the positive electrode to the negative electrode with a voltage source, such that lithium from the positive electrode forms at least a portion of a solid electrolyte interface on the negative electrode; and   coupling the auxiliary electrode to the negative electrode, such that lithium from the auxiliary electrode forms another portion of the solid electrolyte interface on the negative electrode.   
     
     
         25 . The method of  claim 24 , wherein coupling of the auxiliary electrode to the negative electrode occurs during a formation process of the battery prior to an initial discharge of the battery. 
     
     
         26 . The method of  claim 24 , wherein coupling of the auxiliary electrode to the negative electrode occurs after an initial discharge of the battery. 
     
     
         27 . The method of  claim 26 , wherein coupling of the auxiliary electrode to the negative electrode is configured to occur at regular intervals. 
     
     
         28 . The method of  claim 24 , wherein coupling of the auxiliary electrode to the negative electrode occurs prior to charging the battery. 
     
     
         29 . The method of  claim 24 , wherein coupling of the auxiliary electrode to the negative electrode includes coupling a voltage source to the negative electrode and the auxiliary electrode. 
     
     
         30 . The method of  claim 24 , wherein coupling of the auxiliary electrode to the negative electrode includes coupling a resistance to the negative electrode and the auxiliary electrode.