Li-ion storage chemistry of metal layers influences on metal oxides

Abstract

A suitable current collector is a critical criterion for attaining high areal capacity in lithium batteries (LIBs). Here, we discover that the transition metal foam-type current collectors and their corresponding active materials upon a simple oxidation process, enable us to design a strategy for controlling the thickness of active materials toward achieving high areal capacity LIBs. Taking nickel foam (NiF) as a case study, we demonstrated that by calcining it in the air at different temperatures of 500 ℃, 600 ℃, 700 ℃, and 800 ℃, the electrodes exhibit distinct physical properties such as the thickness of active material layers, mechanical strength, and electrochemical properties including the rate capabilities, pseudocapacitive contribution, and lithium-ion diffusion. Ultimately, the optimized anode calcined at 700 °C (700-NiO@NiF) maintains a high reversible areal capacity of 7.6 mAh cm−2@0.4 mA cm−2, and 2.0 mAh cm−2 after 200 cycles@3.0 mA cm−2, We further verify that both cobalt foam and copper foam exhibited similar features like that of NiF by tuning their annealing temperatures, creating more opportunities for maximizing the areal capacity of LIBs.