Ultra High Precision Chargers ‑ UHPC
The UHPC can measure the coulomic efficiency of a Li-ion battery more accurately than most commercially available chargers. The UHPC was built by students in the Dahn group.
The coulomic efficiency (CE) is less than 1.0000(...) because of small parasitic reactions between the charged electrode materials and the electrolyte. The closer the CE is to unity the longer Li-ion cells will last. For Li-ion cells to last several decades, CE's over 0.9999 are required!
By making accurate CE measurements early in cycle life one can draw conclusions about how long cells will last. This allows lifetime estimates to be made in a few weeks; conclusions which could have taken years without these techniques.
Figure 1 - The UHPC
A spin-off company, Novonix, was formed by former Ph.D. student, Chris Burns, and research associate, David Stevens. Novonix now produces the only commercially available ultra-high precision charger with specifications close to that of the Dalhousie UHPC. Novonix has sold over twenty systems around the world as of August 2016.
Figure 2 - Novonix High-Precision Charger
- A.J. Smith, J.C. Burns, S. Trussler, and J.R. Dahn, J. Electrochem. Soc. 157, A196-A202 (2010).
- A.J. Smith, J.C. Burns, and J.R. Dahn, Electrochem. Solid-State Lett. 13, A177-A179 (2010).
- A.J. Smith, J.C. Burns, D. Xiong, and J.R. Dahn J. Electrochem. Soc., 158, A1136-A1142 (2011).
- A.J. Smith, H.M. Dahn, J.C. Burns, and J.R. Dahn, J. Electrochem. Soc., 159, A705-A710 (2012).
- T.M. Bond, J.C. Burns, D.A. Stevens, H.M. Dahn, and J.R. Dahn, J. Electrochem. Soc. J. Electrochem. Soc. 160, A521-A527, (2013).