DE-112020003670-B4 - COMPACT, HIGH-CAPACITY LITHIUM THIN-LAYER BATTERY

Abstract

Method for forming a thin-film battery, wherein the method comprises: Forming a trench in a substrate; Deposition of a stencil on an upper surface of the substrate, with the stencil aligned to the trench; Deposition of a cathode layer in the trench, the cathode layer being in direct contact with the template; and Compressing the cathode layer into the trench to reduce the thickness of the cathode layer.

Inventors

• Paul S. Andry
• Eric Peter Lewandowski
• Dana Alexa Totir

Assignees

• INTERNATIONAL BUSINESS MACHINES CORPORATION

Dates

Publication Date

20260513

Application Date

20200819

Priority Date

20190923

Claims (10)

1. A method for forming a thin-film battery, comprising: forming a trench in a substrate; depositing a stencil on an upper surface of the substrate, the stencil being oriented towards the trench; depositing a cathode layer in the trench, the cathode layer being in direct contact with the stencil; and compressing the cathode layer into the trench to reduce the thickness of the cathode layer.
2. Procedure according to Claim 1 , which further features: depositing a cathode-collector layer along the side walls and bottom of the trench; depositing the cathode layer in the trench; and compressing the cathode layer into the trench to reduce the thickness of the cathode layer.
3. Procedure according to Claim 1 , wherein the deposition of the cathode layer in the trench further features: deposition of the cathode layer along a partial area of the side walls of the template.
4. Procedure according to Claim 1 , wherein the compression of the cathode layer into the trench further comprises: applying isostatic pressure to the cathode layer using a print head.
5. Procedure according to Claim 1 , which further features: deposition of an electrolyte layer on the top of the cathode layer; deposition of an anode layer on the top of the electrolyte layer; and deposition of an anode collector layer on the top of the anode layer.
6. Procedure according to Claim 1 , where the stencil is made from a high-temperature polymer or a low-temperature polymer.
7. Procedure according to Claim 1 , which further features: the addition of an ionic liquid electrolyte to the cathode layer.
8. Procedure according to Claim 1 , wherein the substrate is degenerate doped silicon and wherein, as a result of the fact that the substrate is degenerate doped silicon, a rear cathode contact is structured in the substrate.
9. A method for forming a plurality of thin-film batteries, comprising: forming a plurality of trenches in a substrate, each corresponding to a different battery; forming a plurality of singulation channels in the substrate, each singulation channel being located between the plurality of trenches; and forming each of the batteries according to a method as claimed in any preceding claim.
10. Procedure according to Claim 9 , wherein the majority of singulation channels are formed in the substrate using reactive ion etching.

Description

BACKGROUND The present invention relates generally to a thin-film battery and more specifically to a structure and a method for forming a compact lithium thin-film battery with a high capacity. A typical lithium thin-film battery consists of several layers of materials, including, but not limited to, a cathode, a separator, and an anode. The capacity of such a battery is generally limited by the thickness of the cathode layer and its structure. For example, a thick cathode layer can result in a battery with a high capacity, while a thin cathode layer can lead to a battery with a low capacity. Furthermore, the layers are deposited using thin-film vacuum deposition techniques, such as sputtering or plasma-enhanced chemical vapor deposition. SUMMARY According to one embodiment of the present invention, a method for forming a thin-film battery is provided. The method may comprise: forming a trench in a substrate, depositing a stencil on an upper surface of the substrate, wherein the stencil is oriented towards the trench, depositing a cathode layer in the trench, wherein the cathode layer is in direct contact with the stencil, and compressing the cathode layer into the trench to reduce its thickness. The compression of the cathode layer into the trench may involve applying isostatic pressure to the cathode layer using a printhead. The stencil may be made of a high-temperature polymer or a low-temperature polymer. The process may include: depositing a cathode-collector layer along the side walls and bottom of the trench, depositing a cathode layer within the trench, and compressing the cathode layer into the trench to reduce its thickness. The process may also include: depositing an electrolyte layer on top of the cathode layer, depositing an anode layer on top of the electrolyte layer, and depositing an anode-collector layer on top of the anode layer. According to a further embodiment of the present invention, a method for forming a plurality of thin-film batteries is provided. The method may comprise: forming a plurality of trenches in a substrate, forming a plurality of singulation channels in the substrate, wherein each of the plurality of singulation channels is located between the plurality of trenches, depositing a stencil on an upper surface of the substrate, wherein the stencil is oriented towards the trench, depositing a cathode layer in the plurality of trenches, wherein the cathode layer is in direct contact with the stencil, and compressing the cathode layer into the plurality of trenches to reduce the thickness of the cathode layer. According to a further embodiment of the present invention, a structure is provided. The structure can comprise a cathode-collector layer positioned along a substrate, as well as a cathode layer embedded in the substrate, wherein an upper surface of the cathode layer is substantially flush with an upper surface of the cathode-collector layer. The structure can comprise an anode layer positioned on top of an electrolyte layer, wherein the electrolyte layer separates the cathode layer from the anode layer, an anode-collector layer positioned on top of the anode layer, and an insulator layer positioned on top of the anode-collector layer. BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description, which is given as an example and is not intended to limit the invention exclusively to this, is best understood in conjunction with the accompanying drawings, in which: 1 a cross-sectional view showing a trench created in a substrate according to an exemplary embodiment; 2 a cross-sectional view showing a deposited cathode according to an exemplary embodiment; 3 a cross-sectional view showing an aligned printhead on the top of the cathode according to an exemplary embodiment; 4 a cross-sectional view showing a polished cathode layer according to an exemplary embodiment; 5 a cross-sectional view showing the deposition of further layers on the top side of the polished cathode layer according to an exemplary embodiment; 6 a cross-sectional view showing a cover on the top side of the deposited layers according to an exemplary embodiment; 7 a cross-sectional view showing a plurality of batteries according to an exemplary embodiment; and 8A and 8B Cross-sectional views are shown depicting a plurality of batteries on a substrate according to an exemplary embodiment. The drawings are not necessarily to scale. They are merely schematic representations and are not intended to depict specific parameters of the invention. The drawings are intended only to illustrate typical embodiments of the invention. In the drawings, identical numbering represents identical elements. DETAILED DESCRIPTION Detailed embodiments of the claimed structures and methods are disclosed herein; however, it is understood that the disclosed embodiments are merely illustrative of the claimed structures and methods, which can be implemented in various forms. This invention can, however, be implemented in many