Electrode Coating IP Supports Electrovaya Battery Innovation


A previous post discussed advanced battery maker Electrovaya’s lithium ion polymer technology, which the company says provides faster, more efficient transport of lithium, and therefore greater energy density.

Several years ago, Electrovaya partnered with Tata Motors to work on batteries for electric vehicles in Norway.  Tata, in turn, had invested in a Norwegian lithim ion battery company called Miljøbil Grenland (MG).  In 2012 Electrovaya acquired MG.

In an example of green IP supporting further innovation, Electrovaya recently announced its new generation lithium ion battery technology, which it calls SuperPolymer 20.0.  According to its press release, the MG IP was key to the development of the new battery tech:

The module-level and system-level improvements are a result of intensive development at Electrovaya as well as the addition of intellectual property acquired from Tata Motors through the August 2012 acquisition of Miljobil.

MG is listed as the applicant on at least one international patent application, PCT/IB2011/054738, entitled “Method for manufacturing of slurry for production of battery film” (‘738 Application).

The ‘738 Application is directed to methods for manufacturing a slurry for coating cathode and anode materials in batteries.  More particularly, the invention offers an alternative to the use of solvents for coating the electrode foils.

Some of the solvents used to coat battery electrodes are toxic, flammable, or damaging to the chemical structure of the finished battery.  Thus, it is important to fully remove the solvent from the battery film during production, but removing the last remnants of the solvent down to ppm level is difficult and energy intensive.

The ‘738 Application describes and claims a 7-step method including mixing active materials with a binder into a binder solution, adding an organic carbonate to the binder solution to form a slurry, coating an electrode material with the slurry, evaporating the coating by drying the carbonate, and surface treatment (rolling, baking and finishing) of the electrode material.

According to the ‘738 Application, use of the slurry instead of a solvent to coat the electrode is a better solution because the liquid slurry becomes a component of the battery electrode so it does not need to be completely removed:

By using a liquid which is entered as a component in the finished battery it is not necessary that the liquid is removed completely.  This component will still be added at a later stage in the process.  According to the execution of the available invention, a method for manufacturing of the slurry for coating of battery electrodes is provided, where the slurry, meaning active components and a binder will be diluted with a diluting agent, where the diluting agent is a component of the electrolyte which shall be used in the same lithium battery.

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Eric Lane

Eric Lane, the founder and principal of Green Patent Law, is an intellectual property lawyer and registered U.S. patent attorney in New York and is a member of the bar in New York and California. Eric has more than two decades of experience working with wind, solar PV, CSP, biofuels, and geothermal, energy storage technologies, carbon capture and sequestration, medical devices, data communications, mechanical, chemical, internet and software.