Ultrahigh-Speed Aqueous Copper Electrodes Stabilized by Phosphorylated Interphase.

High-energy metal anodes for large-scale reversible batteries with inexpensive and non-flammable aqueous electrolytes promise the capability of supporting higher current density, satisfactory lifetime, non-toxicity, and low-cost commercial manufacturing, yet remain out of reach due to the lack of reliable electrode-electrolyte interphase engineering. Herein, we demonstrate in situ formed robust interphase on copper metal electrodes (CMEs) induced by a trace amount of potassium dihydrogen phosphate (0.05 M in 1 M CuSO 4 -H 2 O electrolyte) to fulfill all aforementioned requirements. Impressively, an unprecedented ultrahigh-speed copper plating/stripping capability is achieved at 100 mA cm -2  for over 12000 cycles, corresponding to an accumulative areal capacity up to tens of times higher than previously reported CMEs. The use of SEI-protection strategy brings at least an order of magnitude improvement in cycling stability for symmetric cells (Cu||Cu, 2800 h) and full batteries with CMEs using either sulfur cathodes (S||Cu, 1000 cycles without capacity decay) or zinc anodes (Cu||Zn with all-metal electrodes, discharge voltage ∼1.02 V). The comprehensive analysis reveals that the hydrophilic phosphate-rich interphase nanostructures homogenized copper-ion deposition and suppressed nucleation overpotential, enabling dendrite-free CMEs with sustainability and ability to tolerate unusual-high power densities. Our findings represent an elegant forerunner toward the promising goal of metal electrode applications. This article is protected by copyright. All rights reserved.