Editor’s Note: This blog post complements a previous battery post, which explains how to use ion chromatography (IC) to measure inorganic anions in lithium carbonate.
Rechargeable batteries are an increasing part of our daily life as we use more portable electronic devices, including mobile phones. These batteries are also important for the electric car industry — a booming market that is redefining automotive manufacturing.
As the electric vehicle market grows, so does the demand for lithium compounds. Experts estimate that the demand for lithium will soar over the next decade, and with that, comes an increase in demand for lithium carbonate and lithium hydroxide.
Let’s take a closer look at lithium hydroxide, why its demand is on the rise, and how a new analytical method can boost efficiency in the determination of impurities like chloride and sulfate.
Why are lithium-ion batteries important and what are their key components?
Lithium-ion batteries are the most commonly used rechargeable batteries because of their high volumetric energy density. Lithium hydroxide and lithium carbonate are precursors to make lithium compounds, which are critical components of lithium-ion batteries. Most lithium-ion battery producers use lithium carbonate for battery applications, but this trend is changing as lithium hydroxide gains more market.
What is lithium hydroxide and what is it used for?
Lithium hydroxide (LiOH) is a compound obtained from the reaction of lithium carbonate with calcium hydroxide. It’s generally used for making lithium salts (also known as soaps) of stearic and other fatty acids. These are then used as a thickener in lubricating grease. The lithium grease has a high temperature and water resistance and can sustain extreme pressures —characteristics that make it especially suitable for the automotive industry.
Why is lithium hydroxide gaining popularity over lithium carbonate?
Despite lithium hydroxide’s being in lower supply than lithium carbonate, it offers more benefits, such as better power density, which translates into more battery capacity, better safety features and longer life cycles. Some electric vehicle (EV) manufacturers have already been using lithium hydroxide for batteries while others are considering.
In the batteries industry, why is studying lithium hydroxide important?
Measuring and studying lithium hydroxide can help determine lithium salt purity.
One of the key needs for Lithium-ion battery manufacturers is high-purity lithium salts—either lithium carbonate or lithium hydroxide monohydrate. While the current standard is 99.5% pure Li salt, battery manufacturers really want at least 99.9% pure, and are interested in getting 99.99%, or even 99.999% pure product. Low impurity rates in lithium salts are critical to battery performance and safety. Impurities, such as sodium, have led to battery failure, overheating and fires.
Why is it important to determine impurities (like chloride and sulfate) in lithium hydroxide?
Battery recyclers and chemical suppliers have a strong interest in determining impurities like chloride and sulfate in saturated lithium hydroxide and lithium carbonate solutions and using those values to determine the amounts in the solid. Lithium hydroxide must meet stringent purity and quality requirements to be used in the production of lithium-ion batteries.
The purity and consistency of battery-grade lithium hydroxide can directly impact the performance, safety and longevity of the resulting lithium-ion batteries. Manufacturers produce battery-grade lithium hydroxide through various purification and refining processes to achieve the desired high purity and low impurity levels.
Where can I learn more about determining chloride and sulfate in lithium hydroxide?
A recent application note from Thermo Fisher Scientific offers additional insight. It describes a method for the determination of inorganic anions (chloride and sulfate) in a saturated lithium hydroxide solution within 12 minutes using a Thermo Scientific Dionex Reagent-Free Ion Chromatography (RFIC) system with a Thermo Scientific Dionex IonPac™ AS29-Fast-4μm anion-exchange column.
For those in the battery market, the learnings provide new insights into how to determine inorganic anions in saturated lithium hydroxide solution. The new method proved to be:
- highly sensitive (MDL 0.09 mg/L for chloride and 0.13 mg/L for sulfate in saturated lithium hydroxide solution)
- precise (with RSD range of 1-6%)
- accurate (with a recovery range of 91-102%)
To learn more, download the application note: Determination of chloride and sulfate in saturated lithium hydroxide solution.
Related Information
You can find additional information and resources on our Ion Chromatography for Battery Material Testing webpage.
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