Fig. 2: Electrochemical behavior of all-solid-state cells with aluminum-based negative electrodes.

a–f Galvanostatic testing of aluminum and Al_94.5In_5.5 cells at 0.2 mA cm⁻² for the first two cycles, 0.4 mA cm⁻² for the next three cycles, and 0.8 mA cm⁻² for subsequent cycles (24 MPa stack pressure, 5.8 mAh cm⁻² positive electrode loading). a Aluminum|LPSC | NMC cell voltage curves. b Al_94.5In_5.5 | LPSC | NMC cell voltage curves. c dQ/dV curves for the first two cycles of the Al–In cell from (b). d dQ/dV curves comparing the first cycle of the aluminum to the Al–In cell. e Areal capacity with cycling of both cells. f CE with cycling, with the inset showing CE over the first ten cycles. g–j Galvanostatic testing of aluminum and Al_94.5In_5.5 cells at higher current densities (0.8 mA cm⁻² for the first cycle and 6.5 mA cm⁻² for subsequent cycles, 50 MPa stack pressure, 8.3 mAh cm⁻² positive electrode loading). g Aluminum|LPSC | NMC cell voltage curves. h Al_94.5In_5.5 | LPSC | NMC cell voltage curves. i Areal capacity with cycling. j CE with cycling, with the inset showing CE over the first ten cycles; the drop in CE on cycle 2 in the inset is due to the increased current density during this cycle. The increases in capacity in (i) at cycle 65 for Al_94.5In_5.5 and 125 for aluminum are due to slightly increased ambient temperature; all testing was otherwise performed at 25 °C.