TECHNICAL FIELD

Embodiments of the invention relate generally to electrodes including a passivation layer formed thereon prior to receiving an initial charge, in which the electrodes may be combined with a variety of electrolyte compositions (e.g., liquid electrolytes, gel polymer electrolytes, deep eutectic solvents). The passivation layer may comprise a matrix material comprising: (a) a cured propoxylated polymer, (b) an uncured hydrophobic glycol ether, or a combination of (a) and (b). Embodiments of the invention also relate to electrochemical cells including one or more electrodes including a passivation layer formed thereon prior to receiving an initial charge.

BACKGROUND

The majority of today's rechargeable batteries are based on lithium-ion chemistry. While lithium-ion batteries possess the highest practical energy density and cycle life among rechargeable systems, they suffer from safety concerns. A prominent safety concern is related to the organic solvents utilized in such batteries. While these organic solvents can support a wide electrochemical window and enable high energy density, they are flammable and volatile. When combined with an oxygen rich cathode, they increase the potential for thermal runaway and catastrophic failure. As a result, batteries need to be thermally managed and hermetically packaged to ensure safety, which adds undesirable weight to the battery and limits lithium-ion battery architectures to rigid form factors (e.g., rigid casings, etc.). However, several commercial applications including autonomous systems, portable expeditionary power, and/or wearable/biomedical sensors require flexible, lightweight, and safe batteries that do not sacrifice energy density.

BRIEF SUMMARY

Certain embodiments of the invention provide an electrode comprising an electrode-composition including an active electrode species, in which the electrode-composition comprises a first surface, and a passivation layer positioned onto at least a portion of the first surface. In accordance with certain embodiments of the invention, the passivation layer may comprise: (i) a matrix material comprising (a) a cured propoxylated polymer, (b) an uncured hydrophobic glycol ether, or a combination of (a) and (b); and (ii) at least a first electrolyte.

In another aspect, embodiments of the present invention provide an electrochemical cell including an anode comprising an active anode species, a cathode comprising an active cathode species, and an electrolyte composition positioned between and in contact with the anode and the cathode. In accordance with certain embodiments of the invention, at least the anode includes a first passivation layer comprising a first matrix material and at least a first electrolyte distributed throughout the first matrix material. The first passivation layer may be positioned between the active anode species and the electrolyte composition. In accordance with certain embodiments of the invention, the first matrix material comprises: (a) a cured propoxylated polymer, (b) an uncured hydrophobic glycol ether, or a combination of (a) and (b).

In another aspect, embodiments of the present invention provide a method of forming an electrode. Such method, for instance, may include providing or forming an electrode-composition including an active electrode species, in which the electrode-composition comprises a first surface. The method may also include providing or forming a passivation-composition comprising a mixture of a matrix material and at least a first electrolyte in a liquid medium. The method may also include coating at least a portion of the first surface with the passivation-composition to provide a liquid-containing pre-passivation layer on at least a portion of the first surface. The method may also comprise at least one of drying or radically-curing the liquid-containing pre-passivation layer to form a passivation layer comprising the matrix material and the first electrolyte, in which the matrix material comprises: (a) a cured propoxylated polymer, (b) an uncured hydrophobic glycol ether, or a combination of (a) and (b).

In another aspect, embodiments of the present invention provide a method of forming an electrochemical cell. The method may include providing or forming an anode comprising a first passivation layer defining a first anode-surface, providing or forming a cathode, and positioning an electrolyte composition between and in contact with the first anode-surface and the cathode. In accordance with certain embodiments of the invention, the first passivation layer may comprise: (i) a matrix material comprising (a) a cured propoxylated polymer, (b) an uncured hydrophobic glycol ether, or a combination of (a) and (b); and (ii) at least a first electrolyte.

