Cell Stack and Redox Flow Battery Patent Grant

ChangeBridge: Patent Grants - Batteries (H01M)

Published March 31st, 2026

Detected March 31st, 2026

Summary

The USPTO granted patent US12592406B2 to Sumitomo Electric Industries, Ltd. covering a cell stack design for redox flow batteries with improved electrolyte flow management through specific groove configurations. The patent, filed on October 6, 2020, contains 8 claims and specifies permeation resistance ratios (R2/R1) between 7×10⁻¹¹ and 2×10⁻⁴ for optimal electrolyte distribution.

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What changed

The USPTO issued Patent Grant US12592406B2 to Sumitomo Electric Industries, Ltd. for a cell stack design incorporating bipolar plates with introduction and discharge portions for electrolyte, featuring multiple first grooves that control electrolyte flow toward the discharge portion. The patent defines specific permeation resistance parameters (R1 in the electrode, R2 in the grooves) with R2/R1 ratios between 7×10⁻¹¹ and 2×10⁻⁴. The technology addresses electrolyte distribution in stacked battery cells for redox flow battery applications.

Patent grants establish intellectual property rights but do not impose compliance obligations on third parties. Manufacturers developing redox flow battery technology should review the claims to ensure their products do not infringe on Sumitomo's protected design. Companies researching electrolyte flow management in flow batteries may need to obtain licenses or design around the claims. No immediate action is required as this is a patent issuance rather than a regulatory requirement.

Source document (simplified)

← USPTO Patent Grants

Cell stack and redox flow battery

Grant US12592406B2 Kind: B2 Mar 31, 2026

Assignee

Sumitomo Electric Industries, Ltd.

Inventors

Yuta Ochi

Abstract

A cell stack is in which a plurality of battery cells are stacked, including an electrode of a porous body, and a bipolar plate facing the electrode, in which the bipolar plate includes an introduction portion of an electrolyte, a discharge portion of the electrolyte, and a plurality of first grooves extending from a side at which the introduction portion is disposed toward a side at which the discharge portion is disposed, each of the plurality of first grooves allows the electrolyte in each of the plurality of first grooves flow toward the discharge portion, R2/R1 is 7×10−11 or more and 2×10−4 or less, R1 is a permeation resistance indicating a difficulty of a flow of the electrolyte in the electrode, and R2 is a permeation resistance indicating the difficulty of the flow of the electrolyte in each of the plurality of first grooves.