Understanding the anchoring effect on Li plating with Indium Tin oxide layer functionalized hosts for Li metal anodes

Abstract

Li dendrites caused by nonuniform Li plating and locally concentrated ion/electron flux would give rise to poor cycling performance and safety issues of short-circuit and so on. Herein, a functional nanolayer consisting of Indium Tin oxide (ITO) nanoparticles on 3D Cu foam was fabricated as case study to understand the mechanism of metal oxides on anchoring Li metal spots and how initial Li nucleation influences the following dendrites growth. Based on the experimental and theoretical results, it is demonstrated that not only the pristine metal oxides have higher binding energy with Li atom, but also in situ formed alloy phase during alloying process performs a great importance on homogeneous nucleation, thus leading to ordered ion/electron distribution and fast kinetics. Therefore, excellent wettability and even self-propagation behavior between ITO-Cu foam and molten Li are achieved, meanwhile the half cells with ITO-Cu foam electrodes exhibit an ultralow nucleation overpotential of 2 mV under 0.5 mA cm−2. When the designed ITO-Cu foam@Li anodes is matched with LFP (LiFePO4) cathodes, the constructed full cells can empower superior cycling stability for over 1000 cycles at 5C (3.4 mA cm−2), and remarkable specific capacity (149 mAh g−1) and capacity retention (80% for 250 cycles) even with ultrahigh mass loading (15.3 mg cm−2), which provides an avenue to regulate Li deposition/dissolution for high energy Li metal batteries.