SMM News: June 11 news, according to foreign media reports, electric vehicle manufacturer Tesla's battery research team in Canada has filed a new patent application, which is a method of analyzing electrolytes in lithium-ion batteries, which will help prevent battery failure.
The patent was filed by the Tesla battery research team led by Jeff Dan (Jeff Dahn) in Halifax (Halifax). Dan is considered to be a pioneer in the field of lithium-ion batteries. Since the invention of lithium-ion batteries, Dan has been committed to the research of lithium-ion batteries. He helped improve the life cycle of lithium-ion batteries, which helped commercialize them. Dan's work is now focused on improving battery energy density and durability.
In 2016, under the newly formed "NSERC/ Tesla Canadian Industrial Research" (NSERC/Tesla Canada Industrial Research), Dan), the research team ended its 20-year research agreement with 3M and began working with Tesla instead. Through the agreement, Tesla invested in a new research laboratory near the Dan Group near Halifax, Nova Scotia.
Dan hasn't had much news in the past few years, but there have been reports that his team has been working on electrolyte additives to improve the chemical performance of lithium-ion batteries. Earlier this year, the team began applying for a patent for battery technology for Tesla, and today released a new patent, the so-called "method and system for determining the concentration of electrolyte components in lithium-ion batteries."
Dan et al described the invention in a summary of patent applications:
Our technology provides a computer implementation method for determining the concentration of electrolyte components in lithium-ion batteries or lithium-ion batteries. The method includes issuing instructions to the spectrometer to capture the spectrum of the electrolyte sample solution and generate a signal. The method includes analyzing the signal to determine one or more spectral features of the spectrum.
The method includes preparing a spectral database corresponding to a solution having a predetermined electrolyte component concentration, wherein the database includes a spectral database for a plurality of spectral characteristics per solution. The method also includes determining the machine learning (ML) model using a spectral database and determining the concentration of electrolyte components in the sample solution using the machine learning model.
Tesla described the current problems with electrolytes and how to analyze their status:
One of the main reasons for the failure of lithium ion batteries (especially in high voltage batteries) is the degradation of electrolytes, especially on the surface of charging electrodes. The existing methods to solve the battery failure and electrolyte degradation are mainly focused on the electrolyte decomposition product film based on the electrode surface. These films contain chemical components from electrolyte solvents and electrolyte salts, such as lithium hexafluorophosphate (LiPF6).
For example, LiPF6 is decomposed into LiF and PF5, which are easily hydrolyzed into HF and PF3O. These two hydrolysis products have high activity on the electrode, and they inevitably exist in LiPF6 solution, which may adversely affect the performance of the electrode. Although the consumption mechanism of electrolyte solvent and electrolyte salt LiPF6 in lithium ion batteries has been determined, there is no cheap and accurate method to characterize unknown electrolytes to determine the degree of electrolyte degradation.
In general, the quantitative analysis of electrolyte solutions focuses on expensive analytical tools, such as nuclear magnetic resonance spectroscopy (NMR), gas chromatography-mass spectrometry (GC-MS), high performance liquid chromatography (HPLC) and inductively coupled plasma emission spectrometry (ICP-OES). And it takes a lot of time to analyze. In addition, some analytical tools cannot even measure the concentration of electrolyte components directly. For example, the columns or detectors used in chromatographic methods cannot be exposed to the high temperature decomposition products of LiPF6, so these methods focus only on the organic part of the electrolyte.