A new way to measure tetrafluoroborate, perchlorate, and hexafluorophosphate in electrolyte samples
Rechargeable batteries are an increasing part of our daily lives as we use more portable electronic devices, including mobile phones. These batteries are also important for the electric car industry, one of the driving forces in the new global energy economy.
Lithium-ion batteries are the most commonly used rechargeable batteries because of their high volumetric energy density. As the demand for lithium-ion batteries grows, labs must update their equipment and methods for increased battery production.
Let’s take a closer look at lithium-ion battery production and an improved analytical method designed to boost efficiency in the determination of lithium salt anions, including tetrafluoroborate, perchlorate, and hexafluorophosphate, in electrolyte samples designed to stimulate lithium-ion production samples.

What are the key electrolytes of lithium-ion batteries?
The electrolyte in these batteries are lithium salts in non-aqueous solutions. Commonly used lithium salts are lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluorosilicate (LiSiF6), and lithium tetraphenylborate (LiB(C6H5)4).
What organic solvents are typically used in lithium-ion battery production?
Commonly used organic solvents are ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, propylene carbonate, methyl formate, methyl acrylate, methyl butylate, and ethyl acetate. The electrolyte in lithium batteries may have any mixture of these lithium salts and organic solvents.
In the batteries industry, why is studying lithium solutions important?
Measuring and studying lithium salts and organic solvents helps to ensure safe and effective battery production. One of the key needs for Lithium-ion battery manufacturers is high purity lithium salts, where the electrolyte’s concentration in the solvent ranges from 0.1 to 2 M, with an optimal range of 0.8 to 1.2 M. 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.
How is ion chromatography useful in battery production?
The anions of the added lithium salts can be determined by ion chromatography (IC) to ensure that the solutions have been prepared at the proper concentrations.
Where can I learn more about determining anionic content?

A recent application note (AN2026) from Thermo Fisher Scientific offers additional insight. It describes an improved method for the accurate determination of lithium salt anions (including tetrafluoroborate, perchlorate, and hexafluorophosphate) in an electrolyte sample using a Thermo Scientific Dionex Reagent-Free Ion Chromatography (RFIC) system with 2 mm versions of Thermo Scientific Dionex IonPac AS20 Columns which reduces the flow rate by 4-fold and subsequently eluent generator cartridge (EGC) consumption and waste generation by 4-fold compared to its 4mm versions.
The new method also shows improvement in determining lithium salt anions in simulated battery electrolyte solutions. To learn more, download the application note.
Why is the Dionex IonPac AS20 column important in the process?
The Dionex IonPack AS20 column is a hydroxide-selective high-capacity anion-exchange column developed to determine anions that are strongly retained on other anion-exchange columns. With this column, highly retained anions, such as hexafluorophosphate, can be determined with weaker eluents and in less time compared to other anion-exchange columns.
Related information
You can find additional information and resources on our Ion Chromatography for Battery Material Testing webpage.
Blog post: A New Way to Measure Inorganic Anions in Battery-Grade Lithium Carbonate