Cu-modified Ni foams as three-dimensional outer anodes for high-performance hybrid direct coal fuel cells

The hybrid direct coal fuel cell (HDCFC) is a promising technology for the generation of power using coal, which is abundant and cheap. However, restricted contact between the solid carbon in the coal and the anode of the cell not only limits the electrochemical oxidation sites, but also adversely affects the transport of electrons and ions. Herein, we demonstrate a new strategy of using Cu-modified Ni foams as the three-dimensional outer anode for a high-performance HDCFC with 3D structure, that is rich in electrochemical reaction sites and beneficial for electron and ion transport when filled with molten carbonates and anthracite coal. Moreover, the CuNi alloy layer formed on the surface of Ni foam is of excellent coking-resistance and capable of preventing ash-clogging, therefore effectively promoting the durability of an electrolyte-supported HDCFC. An excellent maximum power density of 378 mW cm⁻² at 750 °C is achieved using the prepared 3D anode with anthracite coal as fuel. Besides, the cell exhibited stable operation for more than 13 h at 100 mA cm⁻², promising a new electrode design strategy for developing high-performance HDCFC anodes.