Electrochemical cell including functionally graded and architectured components and methods

Abstract

Electrochemical cells or batteries featuring functional gradations, and having desirable, periodic configurations, and methods for making the same. One or more methods, in alone or in combination, are utilized to fabricate components of such electrochemical cells or batteries, which are designed to achieve certain thermal, mechanical, kinetic and spatial characteristics, and their effects, singly and in all possible combinations, on battery performance. The thermal characteristics relate to temperature distribution during charge and discharge processes. The kinetic characteristics relate to rate performance of the cells or batteries such as the ionic diffusion process and electron conduction. The mechanical characteristics relate to lifetime and efficiency of the cells or batteries such as the strength and moduli of the component materials. Finally, the spatial characteristics relate to the energy and power densities, stress and temperature mitigation mechanisms, and diffusion and conduction enhancements. The electrochemical cells or batteries constructed according to the methods presented in this invention are useful for all applications that require high rate performance, high energy / power density, good durability, high safety and long lifetime.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Patent Application No. 61 / 086,161, filed Aug. 5, 2008, the disclosure of which is hereby incorporated by reference for all purposes.BACKGROUND OF THE INVENTION[0002]The present invention relates generally to electrochemical cells. More particularly, the present invention provides methods and devices having a functionally graded and an architectured component for electrode(s). Merely by way of example, the invention can be applied to a variety of applications including automotive, telecommunication, general energy storage, portable electronics, power tools, power supplies, among others.[0003]As noted, electrochemical cells are used to store energy for a variety of applications. These applications include portable electronics such as cell phones, personal digital assistants, music players, video cameras, and the like. Applications also include power tools, power supplies for military use...

AI Technical Summary

Benefits of technology

[0010]An embodiment of the present invention, one or more material is provided that comprises a microarchitectured morphology having at least one mechanism to mitigate intercalation and thermal expansion stresses, strengthen the electrode material.

[0015]In another embodiment of the present invention, methods are provided that comprise of manipulating the materials to form nanocomposite electrode. A nanocomposite architecture of the cathode material to neutralize internal stresses, stop crack growth, maximize material strength, and stabilize active material structure. A nanocomposite material is formed by depositing two or more layers of same material with different crystal structures. In one embodiment, a nanocomposite material is formed by depositing two or more layers of the same material with different crystal structures, and using masks on alternate layers to create patterns. In another embodiment, a nanocomposite material is formed by depositing two or more layers of different materials. In yet another embodiment, a nanocomposite material is formed by depositing two or more layers of different materials, and using masks on alternate layers to create patterns. In yet another embodiment, a nanocomposite material is formed by depositing two or more materials at the same time to create one or more nanodisperse phases within the main matrix grains of active material. In another embodiment, a nanocomposite material is formed by depositing two or more materials at the same time to create dispersion of secondary phases around the grain boundaries of the matrix of active material. In yet another embodiment, a nanocomposite material is formed by depositing two or more materials at the same time to create a dispersion of secondary phases both inside and around the grains of the matrix of active material. In another embodiment, a nanocomposite material is formed by depositing two or more materials at the same time to induce phase separation. As used herein, the term nanocomposite shall include feature sizes ranging from about 50 Å about 500 nanometers and less, but can be other sizes according to ordinary meaning.

[0017]In another embodiment of the present invention, methods are provided that comprise of masking, and deposition to define a precise morphology of active region for neutralizing internal stresses, stopping crack growth, maximizing material strength, and stabilizing active material structure in anode, electrolyte, cathode and current collectors.

[0026]The benefits of the invention include the ability it confers in rational design and combination of multiple materials to produce electrochemical cells, in novel arrangements. These in, turn, confer superior properties to designed cells, and elimination of costly-trial and error in construction of prototype cells. Depending upon the embodiment, one or more of these benefits can be achieved.

Problems solved by technology

Thus, drawbacks exist with these conventional cells.

The drawbacks include limited lifetime, premature failure, limited storage capability, and other imperfections.

A central challenge to create cost-effectively microarchitectured and functionally graded electrodes, cells or batteries is precisely tuning material properties for the specific role of that material needed.

However, such a process is too costly and can not be used for mass production of high-tech electrochemical cells.

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