The formic acid hydroxyl radical flow battery: a biomimetic batterydesign (FAFB)

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This is an open source patent and can be used by anyone to make a profit and/or change the world.

This electrochemical generator can be referred to as the radical generator, formic acid battery or any other term.

****Results: formic acid (95%) and hydrogen peroxide (35%) with paper separator 0.6 volts.  Acetic acid (99%) and hydrogen peroxide (35%) with paper separator 0.3 volts.  Sodium bicarbonate added to peroxide reduced voltage :(.  Hopefuly with a better membrane we will have better results.

Upon further study it looks like a iron 2 catalyst is needed to convert hydrogen peroxide to OH hydroxyl radical in a fenton type reaction which is enhanced by bicarbonate.

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The formic acid flow battery uses formic acid (or any reducing acid, formic acid being the most preferable, acetic acid also good), hydrogen peroxide (or any peroxide, hydrogen peroxide being the most preferable), a catalyst (such as but not limited to any iron 2 or 3 containing molecule or compound or ion or atom), and optionally bicarbonate ions (or carbonate or carbonic acid or co2; bicarbonate being the most preferable- or any other additive that helps spare h2o2 in the regeneration of the catalyst).  It is believed that the hydrogen peroxide and catalyst form a hydroxyl radical.  Bicarbonate is thought to help improve the conversion efficiency or most probably to help the regeneration of iron 3 back into iron 2 but can be added for any other use as well.  Any other additives can be added as well to improve the cell in any way as long as the cell is producing hydroxyl radical.  The "bicarbonate" (or any previously mentioned alternative or combination) can be isolated or have alkali or alkaline counter ions or molecules like ammonia or combinations such as sodium or potassium or lithium or ammonia etc.  This isolation can be done inside or outside the battery or cell if desired.  One way (but not limited to) this can be done is with membranes and electrical potential

The solutions can be at any pressure including evaporated all the way (vapor phase, even plasma) to high pressure liquids, to solids.  Preferably probably at standard pressure for best practicality.  The solutions or cell or battery can be at any temperature, preferably probably around room temperature or body temperature 37 deg C for greatest practicality.  The liquids can be aqueous or non aqueous with any other additives desired for any purpose such as to improve power density, efficiency, practicality, membrane functionality, creation of the active molecules/compounds, etc.

The battery can either be recharged directly or the solutions replaced or a combination of these.  The battery can have single or multiple cells in series or parallel or combination; in any number or configuration; large or small.  The battery can be used for any use including but not limited to stationary or mobile power storage or generation, automotive applications, personal transportation, powering biologically interfacing devices, etc.

Ideally any separator of any material, shape, or surface area, including multiple layers with any spacing between; including most preferable a polymer membrane between the two solutions would keep the formate ion from crossing and only allow H+ to cross such as in a formic acid fuel cell.  A nafion type membrane would be a very preferable separator.  To make a biomimetic design there could be two membranes with an intermembrane space where bicarbonate/h2o2/h2co4/hco4 could cross from one side and H+ can cross from the other side; but this is not necessary.

Ideally the separator or polymer membrane would also only allow h2o2 and bicarbonate ion to cross from the other side; either separate or as an intermediate such as peroxycarbonate or peroxybicarbonate such as HCO4 or H2CO4; or not allow these ions to cross at all and only allow H+ to cross.

The "peroxycarbonate" (which will be used to imply any such item or combination as laid out above) would be the oxidizing agent on one side and "formic acid" as the reducing agent on the other side.

Each cell can have multiple membranes instead of just one if desired, for example but not limited to this; hydrogen peroxide linked to bicarbonate by a membrane and the bicarbonate linked to formic acid by a membrane.  Also multiple membranes can be use to separate counter ions like potassium from the bicarbonate ions or separate hydrogens from the formate ion.  Any number and in any format in 3 dimensional space can membranes or dividers be used.

The membrane can have any composition but most preferably it would only allow hydrogen ions and peroxy(bi)carbonate intermediates to cross or only hydrogen ions to cross.  Still very preferable would be if it allowed hydrogen ions, bicarbonate ions, and hydrogen peroxide to cross.  Less preferably but still reasonably it would allow anything to cross.  Things can cross directionally, bidirectionally, or omnidirectional; directional being most preferable.  Active transport of the ions or passive transport can be used.  Different solubility and/or density electrolytes could even be used so that no membrane or separator is needed.

Any current collectors or electrodes can be used but preferably noble type metals.  Copper and germanium can also be used as anode material and may make the battery into a hybrid of what is known as a "noble metal battery" which I have described in previous inventions.  Also any reducing gasses like hydrogen on the anode side and any oxidizing gasses like oxygen and nitrous oxide and co2 to the cathode side can be sparged or pressurized or otherwise added in as well making this a hybrid fuel cell.  Adding other molecules or materials to the anode or cathode side as catylysts for any purpose can also be done; including but not limited to photoreceptive compounds on the anode side to make this into a hybrid solar cell; or catalysts to convert oxygen or "air" into hydrogen peroxide, or creating bicarbonate with co2 and a alkali or alkaline metal and an electrical current or any other method.  These things laid out above can be done for any purpose such as recharging, adding additional power etc.  Also palladium or a palladium alloy of 0-100% palladium and any other metal or material may be an ideal material on the anode side since it is good at capturing hydrogen from "formic acid" (quotes used because any reducing acid or combination of reducing acids can be used).  For the cathode a most preferable material may be iridium or an iridium alloy 0-100%.  This is because iridium is the material most resistant to oxidation.  Other noble metals like rhenium, osmium, platinum, gold, ruthenium, etc. can be used as well as refractory metals like zirconium, niobium, tungsten, molybdenum, etc, can be used as well.  Any alloy as well.

The casing can be any material including but not limited to membranes, plastics, metals, etc.  It can be conducting or non-conducting but preferably non conducting.

The final active products h2o2/bicarbonate (or some type of peroxy(bi)carbonate) and H+ ion can be produced by any method and delivered by any method including but not limited to being produced in the battery itself via any method or produced externally and added into the battery automatically or manually.  The solutions can be dumped out of the battery if desired or recycled or recharged with or without dumping.  The solutions can be moved to other areas of the battery or outside the battery for any reason.  Any type of recharging or reforming the solutions can be done by natural (such as but not limited to enzymatically or biologically) or artificial means.