Gas phase deposition of battery separators

Abstract

In certain embodiments, a gas phase deposited porous separator is provided. The porous separator can be deposited onto an electrode. The electrode can include at least one cavity or protrusion, and the separator layer can be gas phase deposited onto a surface of the at least one cavity or protrusion. In certain embodiments, a method of gas phase depositing a separator layer is provided.

1 . A method of making a battery separator comprising:
 gas phase depositing a composition onto an electrode, the composition comprising a first component selected from the group consisting of polymers, dimers and monomers and a second component selected from the group consisting of polymers, dimers and monomers, the first component being different than the second component, the first component and the second component each form separate polymer phases and together form a layer; and   removing at least a portion of the second component to form a porous separator layer.   
     
     
         2 . The method of  claim 1 , wherein the first polymer is a substantially continuous phase in the porous layer. 
     
     
         3 . The method of  claim 1 , further comprising:
 activating a first dimer; and   pyrolysing the first dimer to form the first component.   
     
     
         4 . The method of  claim 3 , further comprising:
 activating a second dimer; and   pyrolysing the second dimer to form the second component.   
     
     
         5 . The method of  claim 3 , wherein the first dimer comprises di-para-xylylene, the first component comprises para-xylylene, and the first polymer comprises parylene. 
     
     
         6 . The method of  claim 1 , wherein the gas phase depositing comprises atomic layer deposition. 
     
     
         7 . The method of  claim 1 , wherein the gas phase depositing comprises plasma deposition. 
     
     
         8 . The method of  claim 1 , wherein the electrode comprises a material that reacts with ions. 
     
     
         9 . The method of  claim 1 , wherein the electrode comprises carbon. 
     
     
         10 . The method of  claim 1 , wherein the porous layer comprises an open cell structure. 
     
     
         11 . The method of  claim 1 , wherein the porous layer comprises parylene. 
     
     
         12 . The method of  claim 1 , wherein the gas phase depositing further comprises reducing the electrode temperature to below room temperature. 
     
     
         13 . The method of  claim 1 , further comprising cross-linking the porous layer. 
     
     
         14 . The method of  claim 1 , wherein the cross-linking the porous layer comprises using at least one cross-linking agent selected from the group consisting of N,N-methyl-bisacrylamide, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and ethylene glycol dimethacrylate. 
     
     
         15 . A method of making a battery separator comprising:
 gas phase depositing a composition onto an electrode, the composition comprising a first component selected from the group consisting of polymers, dimers and monomers;   forming a layer comprising a first polymer from the first component and a second component selected from the group consisting of by-products and remaining portions of the first component from the forming the first polymer; and   removing at least a portion of the second component to form a porous separator layer.   
     
     
         16 . The method of  claim 15 , further comprising controlling process parameters to produce the by-products and the remaining portions of the first component. 
     
     
         17 . The method of  claim 16 , wherein the process parameters are controlled to form the layer with about 10 to 90 vol. % of the second component. 
     
     
         18 . A method of making a battery separator comprising:
 forming a first layer onto an electrode, the first layer comprising a porous template, the porous template comprising a removable material;   gas phase depositing a first component into the porous template, the first component selected from the group consisting of polymers, dimers and monomers; and   removing at least a portion of the porous template to form a porous separator layer comprising the first component.   
     
     
         19 . The method of  claim 18 , further comprising forming a first polymer from the first component. 
     
     
         20 . A method of making a battery separator comprising:
 gas phase depositing a composition onto an electrode, the composition comprising a precursor and a foaming agent;   evaporating the foaming agent to foam the precursor; and   polymerizing the precursor to form a porous separator layer.   
     
     
         21 . The method of  claim 20 , wherein the evaporating the foaming agent is caused by heat produced from the polymerizing the precursor. 
     
     
         22 . The method of  claim 20 , wherein the evaporating the foaming agent comprises pulling a vacuum. 
     
     
         23 . The method of  claim 20 , wherein the precursor comprises a cyanoacrylate. 
     
     
         24 . The method of  claim 20 , wherein the composition comprises a solvent. 
     
     
         25 . The method of  claim 20 , wherein foaming agent is selected from the group consisting of pentane, hexane, 1,1,2-trichlorotriflouroethane, cyclohexane, petroleum ether and diethyl ether. 
     
     
         26 . A battery separator comprising a gas phase deposited porous separator. 
     
     
         27 . The battery separator of  claim 26 , wherein the porous separator has an open cell structure. 
     
     
         28 . The battery separator of  claim 26 , wherein the porous separator comprises parylene. 
     
     
         29 . The battery of  claim 26 , wherein the gas phase deposited separator is a polymer. 
     
     
         30 . A battery electrode and separator comprising:
 an electrode comprising at least one cavity or protrusion on at least one surface of the electrode, the cavity or protrusion having a length greater than about 5 mils and at least one width that is less than about 5 mils; and   a substantially conformal separator layer gas phase deposited onto a surface of the at least one cavity or protrusion.   
     
     
         31 . The battery of  claim 30 , wherein the length of the cavity or protrusion is between about 5 and 100 mils. 
     
     
         32 . The battery of  claim 30 , wherein the at least one width of the cavity or protrusion is between about 1 and 5 mils. 
     
     
         33 . The battery of  claim 30 , wherein the electrode comprises a material that reacts with or absorbs ions. 
     
     
         34 . The battery of  claim 30 , wherein the electrode comprises carbon.