Self-standing tin sulfide film for flexible batteries

Patent metadata

Field	Value
Publication number	US-11177473-B2
Application number	US-202015929608-A
Country	US
Kind code	B2
Filing date	May 12, 2020
Priority date	Jan 25, 2019
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

High-performance flexible batteries are promising energy storage devices for portable and wearable electronics. The major obstacle to develop flexible batteries is the shortage of flexible electrodes with excellent electrochemical performance. Another challenge is the limited progress in the flexible batteries beyond Li-ion because of safety concerns for the Li-based electrochemical system. Accordingly, a self-supported tin sulfide (SnS) porous film (PF) was fabricated as a flexible cathode material in Al-ion battery, which delivers a high specific capacity of 406 mAh/g. A capacity decay rate of 0.03% per cycle was achieved, indicating a good stability. The self-supported and flexible SnS film also shows an outstanding electrochemical performance and stability during dynamic and static bending tests. Microscopic images demonstrated that the porous structure of SnS is beneficial for minimizing the volume expansion during charge/discharge. This leads to an improved structural stability and superior long-term cyclability.

First claim

What is claimed is:

1. A method of forming a flexible electrode comprising the steps of:
electrochemically depositing a tin (Sn) film onto a polished Sn foil for a predetermined length of time;
removing the electrochemically deposited Sn film from the polished Sn foil, such that the electrochemically deposited Sn film is a self-supported Sn film;
performing an electrochemical anodic treatment of the self-supported Sn film, the treatment including the steps of subjecting the self-supported Sn film to a constant voltage for a period of approximately thirty minutes;
forming a self-supported tin oxide (SnO 2 ) porous film from the self-supported Sn film during the step of performing the electrochemical anodic treatment; and
performing a chemical vapor deposition treatment on the self-supported SnO 2 porous film, the treatment including the steps of:
disposing the self-supported SnO 2 porous film in an atmosphere of sulfur (S) for a period of approximately thirty minutes; and
forming a self-supported tin (II) sulfide (SnS) porous film from the self-supported SnO 2 porous film.

2. The method of claim 1 , wherein the formed self-supported SnS porous film has a thickness in a range of 0.1-100 μm.

3. The method of claim 1 , wherein the formed self-supported SnS porous film has an electrical conductivity of 0.606 S/cm.

4. The method of claim 1 , wherein the constant voltage is approximately nine volts.

5. The method of claim 1 , wherein the predetermined length of time is approximately six hours.

6. The method of claim 1 , wherein the step of electrochemically depositing the tin (Sn) film onto the polished Sn foil for the predetermined length of time further comprises forming an aqueous solution as a medium within which electrochemical deposit occurs.

7. The method of claim 1 , wherein the step of electrochemically depositing the tin (Sn) film onto the polished Sn foil for the predetermined length of time further comprises forming a two-electrode deposition system including the polished Sn foil as a cathode and a Sn plate as an anode.

8. The method of claim 1 , wherein the step of performing the chemical vapor deposition treatment on the self-supported SnO 2 porous film further comprises forming an upstream heating zone and a downstream heating zone, disposing an amount of sulfur powder at the upstream heating zone, and disposing the self-supported SnO 2 porous film at the downstream heating zone.

9. The method of claim 8 , further comprising the steps of heating the upstream heating zone to 150° C., and heating the downstream heating zone to 350° C.

10. A flexible aluminum-ion battery comprising:
a tin (II) sulfide (SnS) porous film as an electrode within the flexible aluminum-ion battery;
the SnS porous film of the flexible battery having a reversible specific capacity of 406 mAh/g, such that ion diffusion within the flexible aluminum-ion battery is faster than ion-diffusion within aluminum-ion batteries without the SnS porous film;
wherein the flexible aluminum-ion battery is non-rigid, such that the flexible aluminum-ion battery is capable of bending.

11. The flexible aluminum-ion battery of claim 10 , wherein the SnS porous film has a thickness of approximately 2.3 μm.

12. The flexible aluminum-ion battery of claim 10 , wherein the flexible aluminum-ion battery is capable of bending to form a 90° angle.

13. A method of improving aluminum-ion battery performance comprising the steps of:
electrochemically depositing a tin (Sn) film onto a polished Sn foil for a predetermined length of time;
removing the electrochemically deposited Sn film from the polished Sn foil, such that the electrochemically deposited Sn film is a self-supported Sn film;
performing an electrochemical anodic treatment of the self-supported Sn film, the treatment including the steps of subjecting the self-supported Sn film to a constant voltage for a period of approximately thirty minutes;
forming a self-supported tin oxide (SnO 2 ) porous film from the self-supported Sn film during the step of performing the electrochemical anodic treatment;
performing a chemical vapor deposition treatment on the self-supported SnO 2 porous film, the treatment including the steps of:
disposing the self-supported SnO 2 porous film in an atmosphere of sulfur (S) for a period of approximately thirty minutes; and
forming a self-supported tin (II) sulfide (SnS) porous film from the self-supported SnO 2 porous film; and

disposing the self-supported SnS porous film within a non-rigid aluminum-ion battery as an electrode,
wherein ion diffusion within the aluminum-ion battery is faster than ion-diffusion within aluminum-ion batteries without the SnS porous film, and
wherein the non-rigidity of the aluminum-ion battery is such that the battery is capable of flexing.

14. The method of claim 13 , wherein the step of electrochemically depositing the tin (Sn) film onto the polished Sn foil for the predetermined length of time further comprises forming a two-electrode deposition system including the polished Sn foil as a cathode and a Sn plate as an anode.

15. The method of claim 13 , further comprising a step of bending each of the aluminum-ion battery and the SnS porous film to 90°.

Assignees

• Univ Central Florida Res Found Inc

Inventors

• Yang Yang

Classifications

• H01M4/5815

  Sulfides · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M10/054

  Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium · CPC title

• H01M4/0452

  from solutions · CPC title

• H01M4/387 Primary

  Tin or alloys based on tin · CPC title