Examples of high specific and high volumetric capacity conversion-type cathode materials include, but are not limited to, fluorides, chlorides, sulfides, selenides, and others. For example, fluoride-based cathodes may offer higher potential due to their higher capacities, in some cases exceeding 300 mAh/g (e.g., greater than 1,200 mAh/cm³ at the electrode level). For example, in a Li-free state, FeF₃ offers a theoretical specific capacity of 712 mAh/g; FeF₂ offers a theoretical specific capacity of 571 mAh/g; MnF₃ offers a theoretical specific capacity of 719 mAh/g; CuF₂ offers a theoretical specific capacity of 528 mAh/g; NiF₂ offers a theoretical specific capacity of 554 mAh/g; PbF₂ offers a theoretical specific capacity of 219 mAh/g; BiF₃ offers a theoretical specific capacity of 302 mAh/g; BiF₅ offers a theoretical specific capacity of 441 mAh/g; SnF₂ offers a theoretical specific capacity of 342 mAh/g; SnF₄ offers a theoretical specific capacity of 551 mAh/g; SbF₃ offers a theoretical specific capacity of 450 mAh/g; SbF₅ offers a theoretical specific capacity of 618 mAh/g; CdF₂ offers a theoretical specific capacity of 356 mAh/g; and ZnF₂ offers a theoretical specific capacity of 519 mAh/g. Mixtures (for example, in the form of alloys) of fluorides may offer a theoretical capacity approximately calculated according to the rule of mixtures. The use of mixed metal fluorides may sometimes be advantageous (e.g., may offer higher rates, lower resistance, higher practical capacity, or longer stability). In a fully lithiated state, metal fluorides convert to a composite comprising a mixture of metal and LiF clusters (or nanoparticles). Examples of reversible reactions of conversion-type metal fluoride cathodes may include 2Li+CuF₂?2LiF+Cu for CuF₂-based cathodes or 3Li+FeF₃?3LiF+Fe for FeF₃-based cathodes). It will be appreciated that metal fluoride-based cathodes may be prepared in Li-free, partially lithiated or fully lithiated states. Another example of a possible conversion-type cathode (or, in some cases, anode) material is sulfur (S) (e.g., in a Li-free state) or lithium sulfide (e.g., Li₂S, in a fully lithiated state). In order to reduce dissolution of active material during cycling, to improve electrical conductivity, or to improve mechanical stability of S/Li₂S electrodes, one may utilize formation of porous S, Li₂S, porous S—C composites, Li₂S—C composites, porous S-polymer composites, or other composites comprising S or Li₂S, or both.