Jeffrey Dahn and his research group from Dalhousie University, Nova Scotia has filed for a new patent on lithium battery technology which can power more than a million miles. Dahn holds an exclusive agreement with Tesla and his team has published the testing results on new batteries which according to them can be used as benchmarks for other scientists dealing with similar technologies. The report can be found in the Journal of the Electrochemical Society.
The most innovative section of the battery used by Dahn’s team is the cathode. Different batteries use different types of lithium compounds for achieving good characteristics. Dahn’s team has been investigating on NMC – lithium nickel manganese cobalt oxide. This material has been used by several other electric vehicle makers in the past such as Nissan and Chevrolet but not Tesla. Dahn uses synthetic graphite for anode with the electrode being a blend of lithium salts and several other ionic compounds. These components do not differ much in compositions used by other makers however Dahn’s team used a different technique for the NMC cathode’s structure. The team used large single crystals replacing smaller ones which would develop lesser cracks as the battery goes through charged and discharged states.
Battery research has been mostly focused on increasing the range that can be powered in a single charge. Dahn, on the other hand, has focused on improving the battery’s overall lifetime making it suitable for self-driving taxis and electric trucks that are expected to go through several charges and discharge cycles. The current Tesla battery pack lasts for 300,000 to 500,000 miles which is not enough. On the other hand, batteries in this paper are expected to last 4000 charges – four times more than the present commercial batteries.
Since the paper has been categorized for “benchmarking”, it implies that the batteries mentioned in the paper would not be used by Tesla in its vehicles. Dahn mentioned that these batteries are capable of powering an electric vehicle for more than a million miles while lasting two decades in grid energy storage.
Tesla and Dahn were awarded the patent for a single crystal NMC battery with an additive named ODTO, similar to the description in the paper, which has been described by Dahn’s team in another paper last year. There is still room for improvement in the batteries described in the current paper as the specific energy density of mentioned batteries is lesser than the maximum ability of advanced Li-ion batteries. There is a possibility of Li-ion batteries powering more than 500kms in a single charge.
Reference: Journal of the Electrochemical Society.