Dahn Lab formulates 1 million-mile Li-ion battery: How and why

September 25, 2019 | Case Study

In a benchmarking paper, the Dahn Lab at Dalhousie University achieved 4,000 cycles with NMC 532/graphite that effectively triples the typical lifetime expected from similar Li-ion cells. Researchers employed single-crystal NMC 532 coated with TiO2 to stabilize the cathode, an artificial graphite anode, and electrolyte additives like vinylene carbonate and ethylene sulfate to achieve the long cycle life. All testing materials were procured from commercial suppliers: cathode powders from Li-Fun Technology, artificial graphite from Kaijin, and electrolytes from BASF and Shenzen Capchem. Cells were assembled using typical techniques, save for a vacuum drying step prior to electrolyte filling. Dahn said the 4,000 cycles translated to a vehicle service life in excess of 1 million miles; with a cell-level energy density of roughly 800 Wh/L, there is no longer a trade-off between long cycle life and high energy density in Li-ion batteries.