Lithium Battery with Retained Gel-Electrolyte

Abstract

A microcomposite structure for use as a component of a lithium battery is formed from a liquid phase mixture by the removal of a solvent. The microcomposite structure includes a continuous reticulated solid polymer phase, a formed in situ gel-electrolyte phase, and a solid phase surfactant at the interface between the gel and polymer phases for stabilizing the gel phase within the pores of the solid polymer phase. The liquid phase mixture comprises a polymer blend, an aprotic solvent system for the polymer blend, a substantially dissolved anionic surfactant, and a phase separation liquid that is miscible with the aprotic solvent system, but in which the polymer blend is substantially insoluble. The microcomposite structure is formed by casting the liquid phase mixture on a surface and removing solvent until the microcomposite structure forms.

1 . A battery comprising a plurality of microcomposite structures, each microcomposite structure comprising: 
 a continuous reticulated solid phase polymer blend comprising polyvinyl chloride and polystyrene;    a continuous gel phase polymer blend comprising polyvinyl chloride, polystyrene and a gel forming amount of an aprotic solvent system;    the continuous gel phase being interdispersed with the reticulated solid phase, with interfaces between the solid and gel phases; and    a solid phase anionic surfactant at the interfaces.    
   
   
       2 . The battery of  claim 1  wherein the aprotic solvent system is selected from the group consisting of propylene carbonate, dimethyl carbonate, ethylene carbonate, tetrahydrofuran, butylene carbonate, diethylcarbonate, dipropyl carbonate, ethyl methyl carbonate, 1,2-dimethoxymethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, and 2-methyltetrahydrofuran, and mixtures thereof.  
   
   
       3 . The battery of  claim 1  wherein the solid phase anionic surfactant is selected from the group consisting of lithium styrene sulfonate, lithium salts of alkylaryl sulfonates, and mixtures thereof.  
   
   
       4 . The battery of  claim 1  wherein one of the plurality of microcomposite structures forms an anode, one of the plurality of microcomposite structures forms a cathode, and one of the plurality of microcomposite structures forms a separator between the anode and the cathode.  
   
   
       5 . A liquid solution for use in preparing a microcomposite structure for use in a lithium ion gel electrolyte battery, comprising: 
 a polymer blend comprising polyvinyl chloride and polystyrene;    an aprotic solvent system sufficient to dissolve the polymer blend;    an electrolyte salt;    a phase separation, non-solvent liquid sufficient to promote the formation of solid and gel phases from the polymer blend when the aprotic solvent system is removed, wherein the gel phase is formed within pores of the solid phase;    an anionic surfactant sufficient to stabilize the gel phase in the pores of the solid phase; and    an anionic surfactant solvent system sufficient to dissolve the anionic surfactant.    
   
   
       6 . The liquid solution of  claim 5  wherein the aprotic solvent system is selected from the group consisting of propylene carbonate, dimethyl carbonate, ethylene carbonate, tetrahydrofuran, butylene carbonate, diethylcarbonate, dipropyl carbonate, ethyl methyl carbonate, 1,2-dimethoxymethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, 2-methyltetrahydrofuran, and mixtures thereof.  
   
   
       7 . The liquid solution of  claim 5  wherein the phase separation, non-solvent liquid is selected from the group consisting of hexane, toluene, benzene, tetracholoroethylene, tetrachloroethane, cyclohexane, and mixtures thereof.  
   
   
       8 . The liquid solution of  claim 5  wherein the anionic surfactant is selected from the group consisting of lithium styrene sulfonate, lithium salts of alkylaryl sulfonates, and mixtures thereof.  
   
   
       9 . The liquid solution of  claim 5  wherein the anionic surfactant solvent system is selected from the group consisting of lithium styrene sulfonate, lithium salts of alkylaryl sulfonates, and mixtures thereof.  
   
   
       10 . The liquid solution of  claim 5  wherein the aprotic solvent system is also sufficient to dissolve the electrolyte salt.  
   
   
       11 . The liquid solution of  claim 5  further comprising an electrolyte salt solvent sufficient to dissolve the electrolyte salt.  
   
   
       12 . The liquid solution of  claim 11  wherein the electrolyte salt solvent comprises ethanol and acetone.