about-energy-opensource / about-energy-bpx-parameterisation Goto Github PK

In both BPX JSON example files, there is a numerical error in the expression of the "Entropic change coefficient [V.K-1]" for the graphite (negative electrode) material.

• The numerical value is in mV/K, not V/K. This leads to unphysical behaviour when the BPX JSON is used at temperatures other than the reference temperature (25[degC]).
• The expression includes a lengthy redundant term which is multiplied by 0.

Proposed fix:

Replace

"Entropic change coefficient [V.K-1]": "-0.1112 * x + 0.02914 + 0.3561 * exp(-((x - 0.08309) ** 2) / 0.004616) + 0 * (tanh(63.9 * (x - (0.4955 - 0.1122))) - tanh(63.9 * (x - (0.4955 + 0.1122))))"

with

"Entropic change coefficient [V.K-1]": "(-0.1112 * x + 0. "(-0.1112 * x + 0.02914 + 0.3561 * exp(-((x - 0.08309) ** 2) / 0.004616)) / 1000"