Open Source Electrical Energy Storage Device: Flow Battery Edition
In the realm of renewable energy, a new open-source project is making waves. The Flow Battery Research Collective has recently released detailed designs and instructions for building a zinc-iodide flow battery, a promising innovation for small-scale energy storage. This practical approach merges electronics, electrochemistry, and 3D printing, making it accessible for experimentation and research [1].
The battery's design is centred around an electrochemical cell, divided into two halves, each with its own reservoir and peristaltic pump to circulate the electrolytes. The cell components include brass-backed grafoil (compressed graphite sheets) as current collectors, graphite felt as porous electrodes, and matte photo paper as the separator membrane between the electrolyte chambers. The cell frame and reservoir tanks are 3D-printed from polypropylene for chemical resistance [2].
The electrolyte used in the cell is a mix of zinc chloride and potassium iodide. During charge, zinc deposits on the cathode, and iodine/polyhalogen ions form at the anode. On discharge, zinc dissolves, and iodine ions are reduced back to iodides and chlorides [3].
An open-source potentiostat is used to control charge and discharge cycles programmatically, while an Arduino microcontroller manages the peristaltic pumps that circulate the electrolyte solutions [4]. The design is modular, leveraging off-the-shelf parts and 3D printing, and includes advice such as testing the cell for leaks using distilled water before introducing the electrolytes due to iodine staining [5].
A forum is available for documenting progress or seeking help in the build. This method provides a comprehensive framework based on a recent, open design, ideal for DIY enthusiasts and researchers focused on flow battery development [1].
While the detailed step-by-step wiring or code was not provided in the source, the open-source potentiostat and Arduino pump control imply standard open-hardware control programming patterns are used. The flow battery research collective and associated forums give further practical guidance and troubleshooting assistance [6].
This project embodies a practical approach that makes the zinc-iodide flow battery accessible for experimentation and small-scale energy storage research. With its innovative design, it could potentially lead to the development of high-energy-density flow cells, contributing significantly to grid energy storage [7].
[1] Flow Battery Research Collective. (2025). Design and Build Instructions for a Small Zinc-Iodide Flow Battery. [Online]. Available: https://flowbatteryresearch.org/build-instructions/ [2] Ibid. [3] Ibid. [4] Ibid. [5] Ibid. [6] Ibid. [7] Ibid.
- The open-source flow battery project, led by the Flow Battery Research Collective, not only utilizes Arduino for managing the peristaltic pumps but also employs open-source potentiostat for controlling charge and discharge cycles, showcasing the integration of technology and science in renewable energy.
- The recently released zinc-iodide flow battery design, accessible for research and experimentation, merges technology, through the use of Arduino, with science, particularly electrochemistry, as part of an open-source approach to small-scale energy storage innovation in the realm of renewable energy.
