A newly released patent from Tesla has teased what appears to be a step towards Elon Musk’s one-million-mile battery target. The patent describes a new lithiation process for battery cells, which has the potential to improve the quality of cells and possibly even save on costs.
Tesla has submitted a patent titled “Method for Synthesizing Nickel-Cobalt-Aluminum Electrodes.” The document outlines a new electrode synthesizing method that could be used for battery cell production. The proposed application defines an efficient heating process for Nickel-Cobalt-Aluminum (NCA) electrodes. According to the document, previous heating methods at times cause the formation of a lithium substrate known as L15AIO4, which is an impurity. Lowering the amount of lithium within a battery reduces the presence of the contamination, but also leads to “materials with inferior electrochemical properties.”
As noted in the patent, batteries would heat to a temperature high enough to allow for single crystal growth. The revised ratio of lithium to other metals would limit the formation of impurities during the first heating process. Then, the battery would be heated a second time at a temperature lower than the first heating cycle. Researchers involved in the patent noted that this process helped develop an impurity-free single crystal NCA that allowed battery cells to achieve over 4,000 charge cycles.
The patent outlines the heating process:
“Methods disclosed herein include a first lithiation step, wherein a lithium and an other metal component are present in a first lithium/other metal ratio of less than 1.0 and are sintered at a temperature between 800 and 950°C for a time period between 1 and 24 hours to obtain a first lithiated material. The method further includes a second lithiation step, wherein a lithium and a other metal component are present in a second lithium/other metal ratio and further wherein the first lithiated electrode material is sintered with additional LiOHTLO at between 650 and 760°C for a time period between 1 and 24 hours to obtain a second lithiated material.”
In summary, the use of NCA electrodes in batteries would allow for single-crystal materials to present themselves without impurities. The lack of contaminants could lead to an increased lifespan of the cells altogether, helping Tesla take a giant leap forward in its quest to produce a one-million-mile battery for its vehicles.
Interestingly enough, one of the listed names on the patent is battery expert and researcher Jeff Dahn, who has worked with Tesla in the past. Tesla summoned the help of Dahn, who leads a team of researchers at Canada’s Dalhousie University, to help the electric car maker improve its batteries. Dahn’s research has helped Tesla’s development of high-quality battery cells by inventing new electrode combinations, like the one described in this patent, and electrolyte solutions aimed at further increasing battery life.
Tesla’s batteries are always in a state of improvement, and over the years, the cells that the company utilizes for its vehicles and energy storage systems have gotten more energy-dense. Economies of scale that is made possible with facilities such as Gigafactory Nevada have also gone a long way towards helping Tesla near the $100 per kWh mark, a level that is widely considered the point where electric vehicles could achieve price parity with their internal combustion-powered counterparts.
Apart from its battery patents, Tesla has also been busy acquiring several battery companies. Among these are Maxwell Technologies and Hibar Systems, both of which were developing technologies that would allow for better battery quality and more efficient production costs. Relatively simple developments such as those described in Tesla’s recent patent help this cause too, especially since every little bit of optimization helps.
Tesla’s development of its battery technology could lead to its vehicles lasting 20 to 30 years, far longer than petrol-powered cars. It appears the company is planning to create a product line that could stay with owners for extended periods with relatively no annual maintenance. And that, together with price parity, can very well be the catalyst for society’s acceleration towards sustainability.
The full text of Tesla’s “Method for Synthesizing Nickel-Cobalt-Aluminum Electrodes” patent could be accessed in the document below.