Primary Battery
US-2023387379-A1 · Nov 30, 2023 · US
of iron for aqueous cells
of iron for aqueous cells · Cooperative Patent Classification (CPC)
Electric circuits, power, telecommunications, and semiconductors.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | H01M4/521 |
| Official title | {of iron for aqueous cells} |
| Display label | of iron for aqueous cells |
| Total patents | 70 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is declining.
| Year | Patents |
|---|---|
| 2015 | 12 |
| 2016 | 3 |
| 2017 | 5 |
| 2018 | 7 |
| 2019 | 6 |
| 2020 | 7 |
| 2021 | 8 |
| 2022 | 6 |
| 2023 | 9 |
| 2024 | 1 |
| 2025 | 6 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Method for iron preformation in redox flow batteries
US-2023361331-A1 · Nov 9, 2023 · US
Nickel iron battery employing a coated iron electrode
US-2023126166-A1 · Apr 27, 2023 · US
Continuous coated iron electrode
US-2023129997-A1 · Apr 27, 2023 · US
Positive electrode active material for non-aqueous electrolyte secondary batteries, production method therefor, and non-aqueous electrolyte secondary batteries using said positive electrode active material
US-11637284-B2 · Apr 25, 2023 · US
Lithium secondary battery
US-2023051902-A1 · Feb 16, 2023 · US
Aqueous battery
US-11522170-B2 · Dec 6, 2022 · US
High Efficiency Nickel-Iron Battery
US-2022352498-A1 · Nov 3, 2022 · US
Nanocomposite of a nanoporous material and an active material and method of synthesizing thereof
US-2022223839-A1 · Jul 14, 2022 · US
Method of iron electrode manufacture and articles and systems therefrom
US-2022149359-A1 · May 12, 2022 · US
Redox and ion-adsorption electrodes and energy storage devices
US-11316146-B2 · Apr 26, 2022 · US
Nanocomposite of a nanoporous material and an active material and method of synthesizing thereof
US-11316148-B2 · Apr 26, 2022 · US
Sodium Secondary Battery and Manufacturing Method Thereof
US-2021384558-A1 · Dec 9, 2021 · US
Iron-bearing electrodes for electrochemical cells
US-2021359291-A1 · Nov 18, 2021 · US
Decoupled electrode electrochemical energy storage system
US-2021351425-A1 · Nov 11, 2021 · US
Aqueous battery
US-2021203010-A1 · Jul 1, 2021 · US
Aqueous battery
US-2021159482-A1 · May 27, 2021 · US
Method for iron preformation in redox flow batteries
US-2021135270-A1 · May 6, 2021 · US
Positive electrode and alkaline secondary battery including the same
US-10950848-B2 · Mar 16, 2021 · US
Rechargeable battery using iron negative electrode and manganese oxide positive electrode
US-2021028452-A1 · Jan 28, 2021 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC H01M4/521?
- CPC H01M4/521 is the Cooperative Patent Classification code for “of iron for aqueous cells.”
- How many patents are filed under CPC H01M4/521 (of iron for aqueous cells)?
- Our database includes 70 publications tagged with this CPC code.
- Is patent activity under CPC H01M4/521 growing?
- Publication counts under this code: 1 in 2024 vs 6 in 2025 (latest complete years).