公开(公告)号：US20210359315A1

公开(公告)日：2021-11-18

申请号：US17308890

申请日：2021-05-05

Applicant: ESS Tech, Inc.

Inventor： Yang Song ,  Timothy J. McDonald ,  Kenneth Fisher

IPC: H01M8/04276 ,  H01M8/04119 ,  H01M8/18 ,  H01M8/04298

Abstract: Methods and systems are provided for a redox flow battery system. In one example, a method of operating a redox flow battery system includes switching the redox flow battery system to an idle mode and completely draining electrolytes from one or more electrode compartments of the redox flow battery system. The one or more electrode compartments may be purged with a gas and refilled with fresh electrolytes.

公开(公告)号：US20210242483A1

公开(公告)日：2021-08-05

申请号：US17234462

申请日：2021-04-19

Applicant: ESS TECH, INC.

Inventor： Craig E. Evans

IPC: H01M8/18 ,  H01M4/66 ,  H01M8/0202 ,  H01M50/46

Abstract: Methods and systems are provided for manufacturing a bipolar plate for a redox flow battery. In one example, the bipolar plate is fabricated by a roll-to-roll process. The bipolar plate includes a non-conductive substrate that is coupled to a negative electrode on a first surface and coupled to a positive electrode on a second surface, the first surface opposite of the second surface.

公开(公告)号：US11025072B2

公开(公告)日：2021-06-01

申请号：US16163023

申请日：2018-10-17

Applicant: ESS TECH, INC.

Inventor： Aaron Vanderzanden ,  Steve Ernst

IPC: H02J7/04 ,  H02J7/16 ,  H02J7/00 ,  H01M8/18

Abstract: Systems and methods for operating an electric energy storage system are described. The systems and methods include ways of coupling electric energy storage cell stacks to an electric conductor or bus. The coupling is performed to reduce current flow through contactors and to increase a life span of the contactors.

公开(公告)号：US20210075039A1

公开(公告)日：2021-03-11

申请号：US17099191

申请日：2020-11-16

Applicant: ESS TECH, INC.

Inventor： Yang Song ,  Timothy J. McDonald ,  Thiago Groberg

IPC: H01M8/04537 ,  H01M8/18 ,  H01M8/04858 ,  H01M8/04955

Abstract: Systems and methods for operating an electric energy storage device are described. The systems and methods may generate a state of charge estimate that is based on negative electrode plating. An overall state of charge may be determined from the state of charge estimate that is based on negative electrode plating and a state of charge estimate that is not based on negative electrode plating.

公开(公告)号：US10930949B2

公开(公告)日：2021-02-23

申请号：US16153447

申请日：2018-10-05

Applicant: ESS Tech, Inc.

Inventor： Isaac Walker-Stern ,  Aaron Vanderzanden

IPC: H01M8/04186 ,  H01M8/18 ,  H01M8/04276 ,  H01M8/04955 ,  H01M8/04537

Abstract: Systems and methods for operating an electric energy storage device are described. The systems and methods may reduce a voltage potential between a ground reference and terminals of an electric energy storage device. By lowering the voltage potential, a possibility of unintentionally discharging the electrical energy storage device to ground may be reduced.

公开(公告)号：US10777913B2

公开(公告)日：2020-09-15

申请号：US15891277

申请日：2018-02-07

Applicant: ESS TECH, INC

Inventor： Craig E. Evans ,  Sean Casey

IPC: H01M10/04 ,  H01M2/20 ,  H01M8/0258 ,  H01M8/248 ,  H01M8/2485 ,  H01R4/48 ,  H01M8/18

Abstract: A leaf spring compression system comprising a mechanical assembly for securing a plurality of leaf springs on a battery cell stack of a flow battery system is disclosed. The cell stack may, comprise: a plurality of cells stacked together to form a flow battery; and a compression system comprising at least two tie rods extending through the plurality of cells clamping a spring acting at opposite ends to compress the cells together, the spring contacting at least two fulcrum elements positioned between the tie rods. In this way, the compression system may exert uniform loading on the battery cell stack, while minimizing deflection of pressure plates attached to the cell stack.

公开(公告)号：US20200052319A1

公开(公告)日：2020-02-13

申请号：US16536237

申请日：2019-08-08

Applicant: ESS TECH, INC.

Inventor： Yang Song ,  Craig E. Evans

IPC: H01M8/18 ,  H01M4/36 ,  H01M4/58

Abstract: Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery is adapted with an additive included in a battery electrolyte and an anion exchange membrane separator dividing positive electrolyte from negative electrolyte. An overall system cost of the battery system may be reduced while a storage capacity, energy density and performance may be increased.

公开(公告)号：US20200006744A1

公开(公告)日：2020-01-02

申请号：US16548500

申请日：2019-08-22

Applicant: ESS TECH, INC.

Inventor： Craig Evans ,  Yang Song

IPC: H01M2/36 ,  H01M8/18 ,  H01M8/20 ,  H01M8/04186

Abstract: In one example, a system for a flow cell for a flow battery, comprising: a first flow field; and a polymeric frame, comprising: a top face; a bottom face, opposite the top face; a first side; a second side, opposite the first side; a first electrolyte inlet located on the top face and the first side of the polymeric frame; a first electrolyte outlet located on the top face and the second side of the polymeric frame; a first electrolyte inlet flow path located within the polymeric frame and coupled to the first electrolyte inlet; and a first electrolyte outlet flow path located within the polymeric frame and coupled to the first electrolyte outlet. In this way, shunt currents may be minimized by increasing the length and/or reducing the cross-sectional area of the electrolyte inlet and electrolyte outlet flow paths.

公开(公告)号：US10439197B2

公开(公告)日：2019-10-08

申请号：US15476795

申请日：2017-03-31

Applicant: ESS TECH, INC.

Inventor： Craig Evans ,  Yang Song

IPC: H01M2/36 ,  H01M8/18 ,  H01M8/20 ,  H01M8/04186

Abstract: In one example, a system for a flow cell for a flow battery, comprising: a first flow field; and a polymeric frame, comprising: a top face; a bottom face, opposite the top face; a first side; a second side, opposite the first side; a first electrolyte inlet located on the top face and the first side of the polymeric frame; a first electrolyte outlet located on the top face and the second side of the polymeric frame; a first electrolyte inlet flow path located within the polymeric frame and coupled to the first electrolyte inlet; and a first electrolyte outlet flow path located within the polymeric frame and coupled to the first electrolyte outlet. In this way, shunt currents may be minimized by increasing the length and/or reducing the cross-sectional area of the electrolyte inlet and electrolyte outlet flow paths.

公开(公告)号：US10403919B2

公开(公告)日：2019-09-03

申请号：US15711879

申请日：2017-09-21

Applicant: ESS TECH, INC.

Inventor： Craig E. Evans ,  Yang Song

IPC: H01M8/20 ,  H01M8/18

Abstract: An iron redox flow battery system, comprising a redox electrode, a plating electrolyte tank, a plating electrode, a redox electrolyte tank with additional acid additives that may be introduced into the electrolytes in response to electrolyte pH. The acid additives may act to suppress undesired chemical reactions that create losses within the battery and may be added in response to sensor indications of these reactions.