US Patent 10033036 Metal/oxygen battery with internal oxygen reservoir

An electrochemical cell in one embodiment includes a negative electrode, a positive electrode spaced apart from the negative electrode, a separator positioned between the negative electrode and the positive electrode; and an active material particle within the positive electrode, the active material particle including an outer shell defining a core with a substantially constant volume and including a form of oxygen, the outer shell substantially impervious to oxygen and pervious to lithium.