Tesla Motors Inc. has locked a leading advanced battery researcher into an exclusive partnership designed to help the Palo Alto, Calif., electric-car maker sharply lower the cost of its batteries.

Jeff Dahn, a professor at Dalhousie University in Nova Scotia known for his work innovating lithium-ion batteries like those Tesla uses to power its Model S sedan, will cooperate with Tesla researchers. Now working on a project with 3M Co., he will enter a research partnership with Tesla when his current work is completed.

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