Electrochemical device and electronic device including same

Abstract

This application relates to an electrochemical device and an electronic device including the same. In particular, this application provides an electrochemical device, including a cathode, an anode and an electrolytic solution, where the anode includes a carbon material and hydroxyalkyl methylcellulose, and the electrolytic solution includes propionate. The electrochemical device of this application has excellent cycle, storage and low-temperature performance.

1 . An electrochemical device, comprising a cathode, an anode and an electrolytic solution, wherein the anode comprises a carbon material and hydroxyalkyl methylcellulose, and the electrolytic solution comprises propionate. 
     
     
         2 . The electrochemical device according to  claim 1 , wherein the specific surface area of the carbon material is less than or equal to about 3 m2/g. 
     
     
         3 . The electrochemical device according to  claim 2 , wherein the specific surface area of the carbon material is in a range of about 1.5 m2/g to about 2 m2/g. 
     
     
         4 . The electrochemical device according to  claim 1 , wherein the carbon material is selected from one or more of natural graphite and artificial graphite. 
     
     
         5 . The electrochemical device according to  claim 1 , wherein the carbon material is artificial graphite. 
     
     
         6 . The electrochemical device according to  claim 1 , wherein the anode further comprises one or more of a silicon material, a silicon-carbon composite material, a silicon-oxygen material, an alloy material and a lithium-containing metal composite oxide material. 
     
     
         7 . The electrochemical device according to  claim 1 , wherein the hydroxyalkyl methylcellulose is selected from one or more of hydroxyalkyl methylcellulose sodium and hydroxyalkyl methylcellulose lithium, and the alkyl has 1-8 carbon atoms. 
     
     
         8 . The electrochemical device according to  claim 1 , wherein the propionate is selected from compounds of Formula 1: 
       
         
           
           
               
               
           
         
       
       wherein:
 R1 is ethyl or haloethyl, and 
 R2 is alkyl or haloalkyl having 1-6 carbon atoms. 
 
     
     
         9 . The electrochemical device according to  claim 1 , wherein the propionate is selected from one or more of the following: methyl propionate, ethyl propionate, propyl propionate, butyl propionate, amyl propionate, methyl halopropionate, ethyl halopropionate, propyl halopropionate, butyl halopropionate and amyl halopropionate. 
     
     
         10 . The electrochemical device according to  claim 9 , wherein the propionate is selected from one or more of ethyl propionate and propyl propionate. 
     
     
         11 . The electrochemical device according to  claim 1 , wherein the content of the propionate is about 10% to about 65% based on the total weight of the electrolytic solution. 
     
     
         12 . The electrochemical device according to  claim 1 , wherein the electrolytic solution further comprises an additive, and the additive is selected from one or more of the following: fluorocarbonate, carbon-carbon double bond-containing ethylene carbonate, a sulfur-oxygen double bond-containing compound, a compound having 2-4 cyano groups, a cyclic carboxylate, a cyclic phosphoric anhydride, a carboxylic anhydride, a sulfonic anhydride and a carboxylic sulfonic anhydride. 
     
     
         13 . The electrochemical device according to  claim 12 , wherein the additive is selected from a fluorocarbonate and a compound having 2-4 cyano groups. 
     
     
         14 . The electrochemical device according to  claim 12 , wherein the content of the additive is about 0.01% to about 15% based on the total weight of the electrolytic solution. 
     
     
         15 . The electrochemical device according to  claim 13 , wherein the fluorocarbonate has the formula C═O(OR1)(OR2), wherein R1 and R2 are each selected from alkyl or haloalkyl having 1-6 carbon atoms, wherein at least one of R1 and R2 is selected from fluoroalkyl having 1-6 carbon atoms, and R1 and R2 optionally form a 5- to 7-membered ring along with the atoms to which they are connected. 
     
     
         16 . The electrochemical device according to  claim 13 , wherein the fluorocarbonate is selected from one or more of the following: fluoroethylene carbonate, cis 4,4-difluoroethylene carbonate, trans 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, methyl trifluoromethyl carbonate, methyl trifluoroethyl carbonate and ethyl trifluoroethyl carbonate. 
     
     
         17 . The electrochemical device according to  claim 16 , wherein the fluorocarbonate is fluoroethylene carbonate. 
     
     
         18 . The electrochemical device according to  claim 12 , wherein the content of the propionate is about 1.5 to about 30 times the additive based on the total weight of the electrolyte. 
     
     
         19 . The electrochemical device according to  claim 1 , wherein the electrolytic solution further comprises one or more of the following: LiPF6, LiBF4, LiPO2F2, LiSbF6, LiAsF6, LiC4F9SO3, LiClO4, LiB(C2O4)2 and LiN(CxF2x+1SO2)(CyF2y+1SO2), wherein x and y are integers of 1-5. 
     
     
         20 . An electronic device, comprising an electrochemical device having a cathode, an anode and an electrolytic solution, wherein the anode comprises a carbon material and hydroxyalkyl methylcellulose, and the electrolytic solution comprises propionate.