The measurement of mechanical properties of red phosphorus (RP) and diffusivity of Li, Na, and K in RP allowed the development of a model that simulates the evolution of stresses within an RP particle during alkali-ion charging. We show that RP particles can be charged at high current densities without catastrophic failure of the particle. The model was validated by in situ TEM charging with extreme conditions of anisotropic ion diffusion and high current density.
