Micro electrochemical energy storage cells

Abstract

Thin-film micro-electrochemical energy storage cells (MEESC) such as microbatteries and double-layer capacitors (DLC) are provided. The MEESC comprises two thin layer electrodes, an intermediate thin layer of a solid electrolyte and optionally, a fourth thin current collector layer; said layers being deposited in sequence on a surface of a substrate. The MEESC is characterized in that the substrate is provided with a plurality of through cavities of arbitrary shape, with high aspect ratio. By using the substrate volume, an increase in the total electrode area per volume is accomplished.

1. A thin-film micro-electrochemical energy storage cell (MEESC) in the form of a microbattery, said microbattery comprising:
 a substrate having two surfaces,    a thin layer anode consisting of alkali metal (M), alkali metal alloy or in the charged state consisting of lithiated carbon or graphite,    a thin layer cathode consisting of LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , TiS 2 , V 2 O 5 , V 3 O 8  or lithiated forms of the vanadium oxides,    a solid electrolyte intermediate to said anode and cathode layers, consisting of a tin layer of an ionically conducting or electronically non-conducting material selected from glass, poly(ethylene oxide) based polymer electrolyte or polycrystalline material, and    optionally, a fourth current collector layer;    said anode or cathode layer being deposited in sequence on both surfaces of said substrate, said microbattery being characterized in that the substrate is provided with a plurality of through cavities of arbitrary shape, with an aspect ratio greater than 1, the diameter of said cavities being from about 15μ to about 150μ; said anode, cathode, solid electrolyte layers and optional current collector layer being also deposited throughout the inner surface of said cavities.    
     
     
       2. The microbattery of  claim 1 , wherein the substrate is made of a single crystal or amorphous material. 
     
     
       3. The microbattery of  claim 2 , wherein the substrate material is selected from the group consisting of glass, alumina, semiconductor materials for use in microelectronics and ceramic materials. 
     
     
       4. The microbattery of  claim 3 , wherein the substrate material is made of silicon. 
     
     
       5. The microbattery of  claim 1 , wherein the alkali metal (M) which forms the anode is lithium. 
     
     
       6. A lithium ion type microbattery according to  claim 1 , being fabricated in the discharge state where the cathode is fully lithiated and the alloy, carbon or graphite anode is not charged with lithium. 
     
     
       7. The microbattery of  claim 1 , wherein the through cavities of the substrate are formed by Inductive Coupled Plasma etching. 
     
     
       8. The microbattery of  claim 1 , wherein the through cavities of the substrate have an aspect ratio of between about 2 to about 50. 
     
     
       9. The microbattery of  claim 1 , wherein said cavities have a cylindrical geometry. 
     
     
       10. The microbattery of  claim 1 , wherein the solid electrolyte is a polymer electrolyte based on poly(ethylene oxide) and CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, or mixtures thereof. 
     
     
       11. The microbattery of  claim 1 , wherein the solid electrolyte is selected from Li X PO Y N Z  where 2<x<3, 2y=3z and 0.18<z<0.43, or LiS-SiS 2  glasses doped with up to 5% LiSO 4  or 30% LiI. 
     
     
       12. The microbattery of  claim 1 , wherein the solid electrolyte is a polymer electrolyte and it comprises between about 2 to about 15% (V/V) high surface area of inorganic, nanosize particles of ceramic powder which consists of Al 2 O 3 , SiO 2 , MgO, TiO 2  or mixtures thereof. 
     
     
       13. A thin- film micro - electrochemical energy storage cell  ( MEESC )  in the form of a microbattery of    claim 1   , said microbattery comprising:      a substrate having two surfaces,        a thin layer anode consisting of alkali metal  ( M ),  alkali metal alloy or in the charged state consisting of lithiated carbon or graphite,        a thin layer cathode consisting of LiCoO   2   , LiNiO   2   , LiMn   2   O   4   , TiS   2   , V   2   O   5   V   3   O   8    or lithiated forms of the vanadium oxides,        a solid electrolyte intermediate to said anode and cathode layers, said solid electrolyte comprising a thin layer of Li   2   CO   3    doped with Al, and        optionally, a current collector layer;        said anode or cathode layer being deposited in sequence on both surfaces of said substrate, said microbattery being characterized in that the substrate is provided with a plurality of through cavities of arbitrary shape, with an aspect ratio greater than  1 , the diameter of said cavities being from about  15  μm to about  150  μm;        said anode, cathode, solid electrolyte layers and optional current collector layer being also deposited throughout the inner surface of said cavities.     
     
     
       14. A self-powered semiconductor component comprising a microbattery according to  claim 2 . 
     
     
       15. A thin- film micro - electrochemical energy storage cell  ( MEESC )  in the form of a microbattery, said microbattery comprising:      a substrate having two surfaces and a plurality of through cavities of arbitrary shape, said cavities having an aspect ratio greater than  1  and a diameter from about  15  μm to about  150  μm;        a thin layer anode;        a thin layer cathode; and        a solid electrolyte intermediate said anode and cathode layers;        wherein at least one of said anode and said cathode is deposited on both surfaces of said substrate; and        wherein said anode layer, said cathode layer, and said solid electrolyte intermediate said anode and cathode layers, are deposited throughout the inner surface of said cavities.     
     
     
       16. The MEESC of  claim 15 , wherein said anode is selected from the group consisting of an alkali metal ( M ) , an alkali metal alloy, charged lithiated carbon and charged lithiated graphite.   
     
     
       17. The MEESC of  claim 15 , wherein said cathode is selected from the group consisting of LiCoO 2   , LiNiO   2   , LiMn   2   O   4   , TiS   2   , V   2   O   5   , V   3   O   8    and lithiated vanadium oxides.   
     
     
       18. The MEESC of  claim 15 , wherein said electrolyte includes a thin layer of an ionically conducting and electronically non- conducting material.   
     
     
       19. The MEESC of  claim 15 , further comprising a current collector layer deposited throughout said inner surfaces of said cavities. 
     
     
       20. The MEESC of  claim 15 , wherein said substrate is made of a single crystal or an amorphous material. 
     
     
       21. The MEESC of  claim 15 , wherein said substrate is selected from the group consisting of a glass, alumina, a semiconductor material and a ceramic material. 
     
     
       22. The MEESC of  claim 21 , wherein said semiconductor material is silicon. 
     
     
       23. The MEESC of  claim 16 , wherein said alkali metal ( M )  is lithium.   
     
     
       24. The MEESC of  claim 15  fabricated in the discharge state, wherein said cathode is fully lithiated and said anode is selected from the group consisting of an un- lithiated alloy, un - lithiated carbon and un - lithiated graphite.   
     
     
       25. The MEESC of  claim 15 , wherein said aspect ratio is between about  1  and about  50 . 
     
     
       26. The MEESC of  claim 15 , wherein said cavities have a cylindrical geometry. 
     
     
       27. The MEESC of  claim 15 , wherein said solid electrolyte is a polymer electrolyte based on poly( ethylene oxide ). 
     
     
       28. The MEESC of  claim 15 , wherein said anode, said solid electrolyte and said cathode are also deposited on both opposing sides of said substrate.