Abstract
•Phosphorus/carbon composites were fabricated with graphite, reduced graphene oxide, and single-walled carbon nanotubes.•Carbon nanotubes were the best choice for ensuring the structural integrity of the electrode and cycling stability.•Interconversion between different phosphorus phases is not fully reversible at room temperature, which contributes to the capacity degradation.
In theory, red P is a promising alloying-type anode material for Li-ion batteries (LIBs). However, we are challenged by reports of poor electrochemical performance due to P pulverization. So far, our best approach is to use composites of P and C as these dramatically improve the anode's stability in regards to the lithiation/delithiation process. Admittedly, success is dependent on the C additives providing electronic conductivity and structural integrity to the composite whilst also ensuring an adequate P dispersion. Here, three of the most commonly used C additives (carbon nanotubes, reduced graphene oxide and graphite flakes) are compared in their ability to stabilize the capacity of red P and its adherence to the current collector in a LIB. Our experiments show that nanotubes are the most promising stabilization agents due to their mechanical elasticity, high surface area/pore volume, and superior P uptake of their elastic web-like aggregates. As a result, the adherence of the C/P composite to the current collector is ensured. Notwithstanding the additive's performance, we also observe that the interconversion between different P phases is not fully reversible at room temperature, constituting an added reason for the capacity fade of C/P anodes.