Electrolyte-mediated nanograin intermetallic formation enables superionic conduction and electrode stability in rechargeable batteries

Abstract Toward realizing the high-energy-density rechargeable batteries, self-supporting aluminum (Al) foil has been explored as an emerging anode to replace the graphite anode. However, the implementation of Al foil anodes into the rechargeable batteries has been plagued by limited charge-carrier kinetics, substantial volume variation, and poor electrochemical reversibility. Herein, we introduced an electrolyte-mediated mechanical prelithiation method at relatively low pressure, resulting in a gradient and nanograins intermetallic LiAl layer onto the Al under the consideration of matrix hardness to circumvent the large volume change. The designed electrode can provide superionic conduction, structural integrity, as well as high Coulombic efficiency compared with those of bare Al anode, as evidenced by theoretical calculations and battery experiments. This electrode showed fast-charging (112.3 mAh g−1 at 5 C), ultrastable capacity retention (~100.0% at after 600 cycles), and high Coulombic efficiency >99.7% at 10 C under the high-capacity loading condition in the dual-ion battery. When paired with LiFePO4 cathode, the gradient and nanograins intermetallic electrode render conventional lithium-ion battery long-lasting for 200 cycles, demonstrating the decent interfacial and architectural design for the foil-type electrodes.