The cycling protocol included five repetitions of the following sequence: (1 × 0.2C), (3 × 0.5C), (5 × 1C). Therefore, a complete cycling protocol included 45 cycles. Fig. demonstrates the cycling protocol for Cell 1 out of 7, and the equivalent data for Cells 2-7 can be found in SI Section 1. Acoustic data was acquired using an Olympus Epoch 650 ultrasonic flaw detector and a single 6.35 mm diameter, 5 MHz transducer operating in pulse-echo mode (M110-RM, Evident Scientific). The transducer was secured by a 200 g weight. The ultrasonic settings used are specific to the Olympus detector and are listed in Table . A small amount of silicon-dioxide-based couplant (H-2, Evident Scientific) was applied between the transducer and the cell. The shape of the pulsed waveform, obtained by conducting tests on aluminium, can be found in our previous work .