Peapod-like architectures with CuO microspheres encapsulated within MXene as a conversion electrode for lithium-ion batteries.

Conversion electrode materials allow lithium-ion batteries to achieve high reversible capacities but have the problem of sluggish kinetics derived from their insulating decomposition products, thus hindering their future application. Nanostructures that shorten diffusion distances do not solve the problem as the conversion reaction is always associated with the collapse of the original structure. Here, we demonstrate that MXene would be a good conductive additive for conversion electrode materials and utilize an electrode of CuO incorporated into a MXene scaffold as a model case which demonstrates highly improved cyclability with a capacity of 670 mA h g at 5C after 1000 cycles.