Potassium Hydroxide in Alkaline, NiCd, and NiMH Batteries

Introduction

Potassium hydroxide (KOH), also known as caustic potash, is a strong alkali used as an electrolyte in several battery chemistries. For general industrial product information, see Aozun's potassium hydroxide specifications.

What Does Potassium Hydroxide Do in Batteries?

When dissolved in water, KOH separates into potassium and hydroxide ions. These ions carry charge through the electrolyte while electrons flow through the external circuit. In alkaline zinc–manganese dioxide cells, hydroxide ions also take part in the electrode reactions during discharge.

Which Batteries Use Potassium Hydroxide?

• Alkaline zinc–manganese dioxide batteries. These cells use a zinc negative electrode, a manganese dioxide positive electrode, and an aqueous KOH electrolyte. Standard alkaline AA and AAA cells are generally single-use and are common in remote controls and flashlights.

• Nickel-cadmium (NiCd) batteries. These rechargeable cells use an aqueous KOH electrolyte and a cadmium-based negative electrode. Some aircraft use NiCd batteries for engine starting or emergency backup power.

• Nickel-metal hydride (NiMH) batteries. These rechargeable cells commonly use an aqueous KOH electrolyte and a hydrogen-storage alloy at the negative electrode. Rechargeable AA and AAA cells are familiar examples.

Why Concentration and Carbonate Matter

• Concentration and temperature. Both affect how well a KOH solution conducts ions. Cell manufacturers select the electrolyte concentration for the cell design and expected operating conditions.

• Carbonate formation. KOH can react with carbon dioxide from air to form potassium carbonate. Where the electrolyte specification sets a carbonate limit, check that result on the batch COA alongside the KOH assay.

What to Check When Sourcing KOH for Battery Electrolytes

• Form. Confirm whether your process requires solid flakes or liquid KOH. See our comparison of potassium hydroxide flakes and liquid.

• KOH content. Check the required assay for solid KOH or the concentration for a solution. For liquid KOH, confirm whether the concentration is stated as a percentage by weight.

• Impurity limits. Compare the supplier’s results for potassium carbonate, chloride, iron, and any other specified impurities with your electrolyte requirements. Check the reporting units, such as percent or ppm, when comparing offers.

Handling KOH Electrolyte

KOH electrolyte is corrosive. Avoid direct contact with residue from a leaking battery and follow the manufacturer’s handling instructions. See our guide to potassium hydroxide skin contact and first aid.

Frequently Asked Questions

Is potassium hydroxide used in lithium-ion batteries?

Conventional lithium-ion batteries typically use a lithium salt, such as lithium hexafluorophosphate (LiPF₆), dissolved in organic solvents. Aqueous KOH is common in the alkaline battery chemistries described above.

Can batteries containing KOH be recycled?

Yes. Check the battery label and use a local collection or recycling program that accepts that battery type.

What documents should I request when sourcing KOH?

Ask for a batch certificate of analysis (COA) and a safety data sheet (SDS) for the grade offered. Use the COA to check the batch results against your specification and the SDS to review hazards and handling precautions. See our guide to questions to ask a potassium hydroxide exporter.

Request a Potassium Hydroxide Quote

For a KOH quote, send us your required specification, quantity, and destination port.

Email lisa@aozunchem.com
WhatsApp +86 186 5121 5887