Stabilization of li-ion battery anodes

Abstract

Li-ion batteries are provided that include a cathode, an anode comprising active particles, an electrolyte ionically coupling the anode and the cathode, a separator electrically separating the anode and the cathode, and at least one hydrofluoric acid neutralizing agent incorporated into the anode or the separator. Li-ion batteries are also provided that include a cathode, an anode comprising active particles, an electrolyte ionically coupling the anode and the cathode, and a separator electrically separating the anode and the cathode, where the electrolyte may be formed from a mixture of an imide salt and at least one salt selected from the group consisting of LiPF 6 , LiBF 4 , and LiClO 4 . Li-ion battery anodes are also provided that include an active material core and a protective coating at least partially encasing the active material core, where the protective coating comprises a material that is resistant to hydrofluoric acid permeation.

1 . A Li-ion battery, comprising:
 a cathode;   an anode comprising a plurality of particles;   an electrolyte ionically coupling the anode and the cathode; and   a separator electrically separating the anode and the cathode,   wherein each of the plurality of particles comprises:   an active material core comprising silicon (Si);   an inner protective coating around the active material core, the inner protective coating being electrically and ionically conductive, the inner protective coating comprising carbon; and   an outer protective coating around the inner protective coating, the outer protective coating comprising a ceramic, the outer protective coating being Li-ion permeable and electrolyte solvent impermeable.   
     
     
         2 . The Li-ion battery of  claim 1 , wherein:
 the ceramic is selected from aluminum oxide, lithiated aluminum oxide, titanium oxide, lithiated titanium oxide, zinc oxide, lithiated zinc oxide, niobium oxide, lithiated niobium oxide, tantalum oxide, lithiated tantalum oxide, vanadium fluoride, vanadium oxyfluoride, iron fluoride, iron oxyfluoride, aluminum fluoride, aluminum oxyfluoride, titanium fluoride, titanium oxyfluoride, zinc fluoride, zinc oxyfluoride, niobium fluoride, niobium oxyfluoride, tantalum fluoride, tantalum oxyfluoride, nickel fluoride, nickel oxyfluoride, magnesium fluoride, magnesium oxyfluoride, copper fluoride, copper oxyfluoride, manganese fluoride, and manganese oxyfluoride.   
     
     
         3 . The Li-ion battery of  claim 1 , wherein:
 the outer protective coating is mechanically stable during delithiation of the active material core.   
     
     
         4 . The Li-ion battery of  claim 1 , wherein:
 the inner protective coating comprises multiple pores when the active material core is in a delithiated state.   
     
     
         5 . The Li-ion battery of  claim 1 , wherein:
 the outer protective coating comprises a polymer or carbon conductive layer.   
     
     
         6 . The Li-ion battery of  claim 1 , wherein:
 the electrolyte comprises one or more imide salts selected from CF 3 SO 2 N − (Li + )SO 2 CF 3 , CF 3 CF 2 SO 2 N − (Li + )SO 2 CF 3 , CF 3 CF 2 SO 2 N − (Li + )SO 2 CF 2 CF 3 , F 3 SO 2 N − (Li + )SO 2 CF 2 OCF 3 , CF 3 OCF 2 SO 2 N − (Li + )SO 2 CF 2 OCF 3 , C 6 F 5 SO 2 N − (Li + )SO 2 CF 3 , C 6 F 5 SO 2 N − (Li + )SO 2 C 6 F 5  and CF 3 SO 2 N − (Li + )SO 2 PhCF 3 .   
     
     
         7 . The Li-ion battery of  claim 6 , wherein:
 the one or more imide salts make up between about 50 wt. % and about 95% of the electrolyte by weight.   
     
     
         8 . The Li-ion battery of  claim 1 , wherein:
 the electrolyte comprises a salt selected from lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), and lithium perchlorate (LiClO 4 ).   
     
     
         9 . The Li-ion battery of  claim 1 , wherein:
 the electrolyte comprises one or more carbonate solvents selected from ethylene carbonate (C 3 H 4 O 3 ), dimethyl carbonate (C 3 H 6 O 3 ), and ethyl methyl carbonate (C 4 H 8 O 3 ).   
     
     
         10 . The Li-ion battery of  claim 1 , wherein:
 the electrolyte comprises dimethyl acetamide (DMAC).