Solid-state multi-layer electrolyte, electrochemical cell and battery including the electrolyte, and method of forming same

Abstract

An electrochemical cell including a multi-layer solid-state electrolyte, a battery including the cell, and a method of forming the battery and cell are disclosed. The electrolyte includes a first layer that is compatible with the anode of the cell and a second layer that is compatible with the cathode of the cell. The cell exhibits improved performance compared to cells including a single-layer electrolyte.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of provisional application No. 61 / 453,787, entitled Double Layer Construction for All-Solid-State Lithium Ion Batteries, filed Mar. 17, 2011, the contents of which are hereby incorporated herein by reference to the extent the prior disclosure is not inconsistent with the present disclosure.GOVERNMENT LICENSE RIGHTS[0002]This invention was made with government support under grant number N66001-10-1-4007 awarded by DOD / DARPA. The government has certain rights in the invention.FIELD OF INVENTION[0003]The present invention relates generally to batteries and components thereof. More particularly, the invention relates to electrochemical cells including a solid-state electrolyte, to batteries including the electrochemical cells, and to methods of forming and using the batteries, electrochemical cells and components.BACKGROUND OF THE INVENTION[0004]Lithium-ion batteries have become increasingly popular in rece...

AI Technical Summary

Benefits of technology

[0007]The present invention generally relates to electrochemical cells, batteries including the cells, and to methods of forming the batteries and cells. More particularly, the invention relates to electrochemical cells including a multi-layer solid electrolyte, which allows for, among other things, use of lithium metal as an anode. As set forth in more detail below, the cells and batteries formed in accordance with various examples of the invention exhibit superior cycling performance and lower capacity loss, compared to similar cells and batteries including single-layer electrolytes, and allow for use of lithium as anode material and relatively high voltage electroactive cathode material.

[0008]In accordance with exemplary embodiments of the invention, a solid-state electrochemical cell includes an anode (e.g., comprising lithium), a cathode comprising electroactive cathode material (e.g., high voltage electroactive cathode material), and a multi-layer solid-state electrolyte interposed between the anode and the cathode, wherein the multi-layer solid-state electrolyte includes a first electrolyte layer that is stable (does not degrade or degrades at a relatively low rate) with respect to the anode and a second electrolyte layer that is stable with regard to the electroactive cathode material. In accordance with various aspects of these embodiments, the cathode comprises an oxide material, an electrically-conducting carbon material, and second electrolyte layer material. In accordance with further aspects, the cathode further comprises material (e.g., an oxide) overlying the electroactive cathode material to mitigate undesired reactions between the electrolyte and the cathode. The coating may be heat treated to improve cell performance. In accordance with yet further aspects of the invention, the second electrolyte layer is heat treated to increase cell performance.

Problems solved by technology

Although such cells may work for some applications, the liquid electrolytes employed in such cells may leak from the cells and are often flammable; therefore use of such batteries can pose safety hazards.

Unfortunately, however, solid-state cells generally have relatively low ionic conductivity through the solid electrolyte, poor rate capability, and insufficient loading of active material, compared to traditional lithium-ion cells, having a liquid electrolyte.

In addition, solid-state cells often exhibit interfacial instability.

The lithium metal tends to react with and degrade or break down the electrolyte, which causes irreversible cycling of and therefore shortened cycle life of the solid-state cells.

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