Tesla has patented a new battery cell with a tabless electrode that Elon Musk hypes as "way more important than it sounds."
In the new patent application published today, Tesla explains constraints with current battery cells:
Current cells use a jelly-roll design in which the cathode, anode, and separators are rolled together and have a cathode tab and an anode tab to connect to the positive and negative terminals of the cell can. The path of the current necessarily travels through these tabs to connectors on the outside of the battery cell. However, ohmic resistance is increased with distance when current must travel all the way along the cathode or anode to the tab and out of the cell. Furthermore, because the tabs are additional components, they increase costs and present manufacturing challenges.
The new patent called "Cell with a Tabless Electrode" describes a new way to build cells in order to avoid this issue.
Tesla wrote in the patent application:
A cell of an energy storage device with at least one electrode that is tabless, and methods of forming thereof, are described. The cell includes a first substrate having a first coating disposed thereon, wherein a second portion of the first substrate at a proximal end along the width of the first substrate comprises a conductive material. An inner separator is disposed over the first substrate. A second substrate is disposed over the inner separator. The second substrate has a second coating disposed thereon. The first substrate, the inner separator, and the second substrate in a successive manner, the first substrate, the inner separator, and the second substrate are rolled about a central axis.
Here are several drawings that Tesla released in the patent application:
Recently, Tesla has been applying for a lot of intellectual property related to battery cells, like a new electrode for its 1-million-mile battery.
As we previously reported, Electrek revealed that Tesla is working on an internal secret Roadrunner project.
The goal is for Tesla to produce its own battery cells using technologies developed by Tesla's internal teams, including work from Dahn's team, and new technologies recently acquired through the acquisition of Maxwell, on a massive scale and at a cost below $100 per kWh.
For this particular new tabless electrode, CEO Elon Musk said on Twitter that this technology is "way more important than it sounds" without explaining more.
More is expected to be announced at Tesla's battery day in a few weeks.
Here's the patent application in full: