Cathode material for lithium-air battery and method of manufacturing cathode using same

Abstract

The present invention relates to a cathode material for a lithium-air battery and a method of manufacturing a cathode using the same. The cathode material of the present invention includes a solvent component and thus includes an electrolyte in a small amount compared to a conventional cathode material, thereby reducing the weight of a cathode manufactured using the cathode material, ultimately increasing the energy density of a lithium-air battery including the cathode.

1 .- 13 . (canceled) 
     
     
         14 . A cathode, comprising:
 a current collector; and   a cathode layer formed on the current collector and comprising a cathode material,   wherein the cathode material comprises a carbon material, an electrolyte, and a binder,   wherein the electrolyte comprises a lithium salt and an ionic liquid, and   wherein the cathode layer has a thickness of 700 to 1000 μm.   
     
     
         15 . The cathode of  claim 14 , wherein the carbon material comprises one or more selected from the group consisting of carbon nanotubes (CNTs), carbon nanofibers, carbon nanobelts and mixtures thereof. 
     
     
         16 . The cathode of  claim 14 , wherein the ionic liquid comprises one or more selected from the group consisting of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI), diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]), dimethylpropylammonium trifluoromethanesulfonate ([dmpa][TfO]), diethylmethylammonium trifluoromethanesulfonylimide ([dema][TFSI]), methylpropylpiperidinium trifluoromethanesulfonylimide ([mpp][TFSI]) and mixtures thereof. 
     
     
         17 . The cathode of  claim 14 , wherein the cathode comprises a carbon material loaded in an amount of 3.00 to 6.00 mg/cm 2 . 
     
     
         18 . The cathode of  claim 14 , wherein the binder comprises poly(diallyldimethylammonium) bis (trifluoromethanesulfonyl)imide (PDDA-TFSI). 
     
     
         19 . The cathode of  claim 14 , wherein an amount of the binder is 15 to 25 parts by weight based on 100 parts by weight of the carbon material. 
     
     
         20 . The cathode of  claim 14 , wherein a mass ratio of the carbon material and the electrolyte is 1:2-20. 
     
     
         21 . A method of manufacturing a cathode, comprising:
 preparing a cathode slurry comprising a cathode material;   forming a cathode layer by applying the cathode slurry on a current collector; and   heat-treating the cathode layer,   wherein the cathode material comprises a carbon material, an electrolyte, a solvent component and a binder,   wherein the electrolyte comprises a lithium salt and an ionic liquid, and wherein the cathode layer has a thickness of 700 to 1000 μm.   
     
     
         22 . The method of  claim 21 , wherein the solvent component comprises N-methyl-2-pyrrolidone (NMP). 
     
     
         23 . The method of  claim 21 , wherein the heat-treating is performed in a vacuum at room temperature for 22 to 48 hr. 
     
     
         24 . The method of  claim 21 , wherein a mass ratio of the carbon material and the electrolyte is 1:2-20. 
     
     
         25 . The method of  claim 21 , wherein an amount of the solvent component is 50 to 250 mL per g of the carbon material. 
     
     
         26 . A lithium-air battery, comprising:
 the cathode of  claim 14 ;   an anode enabling deposition and dissociation of lithium; and   a polymer electrolyte interposed between the cathode and the anode.