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Tesla improves on its ‘million-mile battery’ with less cobalt and higher energy density

Tesla has made even more battery improvements on its new ‘million-mile battery’ now with less cobalt, which could result in lower cost and even more energy density.

Last year, we were the first to report on Tesla’s battery research partner, Jeff Dahn and his team at Dalhousie University, unveiling the impressive results of tests on a new battery cell that could last over 1 million miles in an electric vehicle.

The new battery tested is a Li-ion battery cell with a next-generation “single crystal” NMC 532 cathode and a new advanced electrolyte, which they patented.

They were able to show over 4,000 cycles in the battery cells made with the novel cathode.

Building on the research done on that battery, Dahn and his students Yulong Liu and Jessie Harlow have published a new research paper called ‘Microstructural Observations of “Single Crystal” Positive Electrode Materials Before and After Long Term Cycling by Cross-section Scanning Electron Microscopy’ in the Journal of The Electrochemical Society.

In the paper, they showed how they achieved high cycling data for NMC 622 and NMC 811 batteries while using even less cobalt than in NMC 532 and achieving even greater energy density.

In the paper, the researchers call some of the results of their testing “exceptional” due to the high cyclability while maintaining strong performance.

A source familiar with the matter told Electrek that this new chemistry would be used in Tesla’s stationary energy storage products, like Powerwall, Powerpack, and Megapack, and it could already be in production.

Tesla conducts its own battery cell development and has Panasonic produce the cells with the new chemistry, but we also recently learned that Tesla is moving to produce its own battery cells.

Electrek previously 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.

Tesla has already tested prototype cells under the Roadrunner secret project. It believes it can produce the cells in volume and use them in its vehicles and eventually in its stationary energy storage products.

The automaker has been developing manufacturing equipment in secrecy, like the pilot production line in Fremont, over the last few months.

We expect Tesla to release more details during its ‘Battery Day’ which is supposed to happen by the end of the month.

Electrek’s Take

This is exciting.

Tesla’s stationary energy storage products are already industry-leading, but if Tesla can improve on longevity while reducing the cost, which is often what happens when you reduce the amount of cobalt in the cell, that will be a big win.

In this paper, Tesla is showing cells with 20% in the cathode, which is about half of what they were previously producing.

I think battery day is looking more interesting by the day.

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