An Anode-Free Zn-MnO2 Battery

Aqueous Zn-based batteries are attractive because of the low cost and high theoretical capacity of the Zn metal anode. However, the Zn-based batteries developed so far utilize an excess amount of Zn (i.e., thick Zn metal anode), which decreases the energy density of the whole battery. Herein, we demonstrate an anode-free design (i.e., zero-excess Zn), which is enabled by employing a nanocarbon nucleation layer. Electrochemical studies show that this design allows for uniform Zn electrodeposition with high efficiency and stability over a range of current densities and plating capacities. Using this anode-free configuration, we showcase a Zn-MnO2 battery prototype, showing 68.2% capacity retention after 80 cycles. Our anode-free design opens a new direction for implementing aqueous Zn-based batteries in energy storage systems.

Automated summary

Aqueous Zn-based batteries are promising due to their low cost and high capacity, but existing designs use excess Zn which reduces energy density. A new anode-free design utilizing nanocarbon nucleation layer enables uniform Zn electrodeposition with high efficiency and stability across various current densities. This innovation opens up new possibilities for implementing Zn-based batteries in energy storage systems.