In accordance with one embodiment, an electrochemical cell includes a negative electrode including a form of lithium, a positive electrode spaced apart from the negative electrode and including an electron conducting matrix and a lithium insertion material wherein Li2O2 is formed as a discharge product, a separator positioned between the negative electrode and the positive electrode, an electrolyte including a salt, and a polymer coating on the lithium insertion material, the polymer coating permeable to lithium ions and impermeable to the electrolyte.