Impedance-based forecasting of battery performance amid uneven usage

Dataset of 88 commercial lithium-ion coin cells cycled under multistage constant current charging/discharging, with currents randomly changed between cycles to emulate realistic use patterns.

raw-data.zip contains the following data:

Variable Discharge: We subject 24 Powerstream LiR2032 coin cells (of nominal capacity 1C = 35mAh) to a sequence of randomly selected charge and discharge currents at room temperature for 110-120 full charge/discharge cycles. Each cycle consists of acquisition of the galvanostatic EIS spectrum, followed by a charging and discharging stage. We collect impedance measurements at 57 frequencies uniformly distributed in the log domain in the range 0.02Hz-20kHz. Charging consists of a two stage Constant Current (CC) protocol; currents are randomly selected in the ranges 70mA-140mA (2C-4C) and 35mA-105mA (1C-3C) in stages 1 and 2 respectively. If the safety threshold voltage of 4.3V is reached before the time limit then charging is stopped. During discharging, a single constant discharge current, randomly selected in the range 35mA-140mA (1C-4C), is applied, until the voltage drops to 3.0V.

Fixed Discharge: We subject an additional 16 Powerstream LiR2032 coin cells (of nominal capacity 1C = 35mAh) to the same cycling conditions as above, except now fixing the discharge current for all cells and cycles at 52.5mA (1.5C) instead of randomly changing the discharge current at each cycle.

chemistry2-25C.zip contains the following data:

Variable Discharge @ 25C: We subject 32 RS-Pro LiR2032 coin cells (of nominal capacity 1C = 40mAh) to a sequence of randomly selected charge and discharge currents at room temperature for 110-120 full charge/discharge cycles. Each cycle consists of acquisition of the galvanostatic EIS spectrum, followed by a charging and discharging stage. We collect impedance measurements at 57 frequencies uniformly distributed in the log domain in the range 0.02Hz-20kHz. Charging consists of a two stage Constant Current (CC) protocol; currents are randomly selected in the ranges 70mA-140mA (2C-4C) and 35mA-105mA (1C-3C) in stages 1 and 2 respectively. The distributions of currents are varied across different cell batches. If the safety threshold voltage of 4.3V is reached before the time limit then charging is stopped. During discharging, a single constant discharge current, randomly selected in the range 35mA-140mA (1C-4C), is applied, until the voltage drops to 3.0V.

Variable Discharge @ 35C: We repeat the experiment conducted above for 16 additional RSPro cells, except that now we cycle the cells at 35C instead of 25C.