Protection of battery electrodes against side reactions

A method of fabricating a battery electrode composition for a battery, the method comprising:

• forming porous electrode particles that each comprise active material provided to store and release ions during battery operation;
• and
• infiltrating, into the porous electrode particles, a filler material occupying at least a portion of the pores of each porous electrode particle to produce composite particles, each composite particle being a composite of one of the porous electrode particles and a portion of the filler material,
• wherein the filler material comprises a liquid and is not substantially conductive with respect to electron transport, and
• wherein the filler material in the battery electrode composition is configured so as to substantially prevent direct contact between the active material and at least one component of an electrolyte used in the battery once the battery electrode composition is made part of an electrode of the battery.