The invention claimed is:1. A metal-ion battery cell, comprising:an anode electrode with a capacity loading in the range of 4 mAh/cm2 to about 10 mAh/cm2 and comprising anode particles including an active material and having an average particle size in the range of about 0.2 microns to about 40 microns, the active material comprising one or more of silicon, germanium, antimony, aluminum, magnesium, zinc, gallium, arsenic, phosphorous, silver, cadmium, indium, tin, lead, bismuth, or an alloy thereof;a cathode electrode;a separator electrically separating the anode electrode and the cathode electrode; andan electrolyte ionically coupling the anode electrode and the cathode electrode, wherein the electrolyte comprises (i) a metal-ion salt composition and (ii) a solvent composition comprising a low-melting point solvent composition with a melting point below about ?70° C. and a boiling point above +70° C.,wherein the low-melting point solvent composition constitutes a volume fraction of the solvent composition that is in the range of 10 vol. % to 95 vol. %.2. The battery cell of claim 1, wherein the average particle size is in the range of about 0.4 microns to about 20 microns.3. The battery cell of claim 1, wherein the anode particles have a specific surface area in the range of about 0.3 m2/g to about 60 m2/g.4. The battery cell of claim 1, wherein one or more low-melting point solvents of the low-melting point solvent composition comprise one or more phosphorous-comprising solvents, one or more esters, one or more ethers, one or more fluorinated solvents, or a combination thereof.5. The battery cell of claim 4, wherein the one or more low-melting point solvents comprise the one or more esters.6. The battery cell of claim 5, wherein at least about 50 vol. % of the one or more esters have a carbon backbone with five carbon atoms.7. The battery cell of claim 1, wherein the solvent composition further comprises two or more regular-melting point solvents, in addition to the low-melting point solvent composition, that each have a melting point above about ?60° C.8. The battery cell of claim 7, wherein the two or more regular-melting point solvents constitute a volume fraction of the solvent composition that is at least about 30 vol. %.9. The battery cell of claim 7, wherein the two or more regular-melting point solvents comprise two or more solvents selected from the group consisting of: carbonates, sulfones, lactones, phosphorus-comprising solvents, silicon-comprising solvents, sulfur-comprising solvents, esters, or a combination thereof.10. The battery cell of claim 9, wherein the two or more regular-melting point solvents comprise one or more linear carbonates and one or more cyclic carbonates.11. The battery cell of claim 7, wherein the two or more regular-melting point solvents comprise a fluorinated solvent that constitutes a volume fraction of the solvent composition that is in the range of about 1 vol. % to about 20 vol. %.12. The battery cell of claim 7, wherein the two or more regular-melting point solvents comprise a phosphorous-based solvent that constitutes a volume fraction of the solvent composition that is in the range of about 0.1 vol. % to about 5 vol. %.13. The battery cell of claim 7, wherein the two or more regular-melting point solvents comprise a vinylene carbonate solvent that constitutes a volume fraction of the solvent composition that is in the range of about 0.1 vol. % to about 3 vol. %.14. The battery cell of claim 1, wherein the metal-ion salt composition is present in the electrolyte at a concentration in the range of about 1.2 M to about 2 M.15. The battery cell of claim 1, wherein the metal-ion salt composition comprises LiPF6, LiBOB, LiFSI, or a combination thereof.16. The battery cell of claim 1, wherein the metal-ion salt composition comprises two or more metal-ion salts.17. The battery cell of claim 16, wherein the two or more metal-ion salts comprise (i) a first metal-ion salt including a first metal ion species and (ii) a second metal-ion salt including a second metal ion species, wherein the first and second metal ion species are the same.18. The battery cell of claim 16, wherein the two or more metal-ion salts comprise (i) a first metal-ion salt including a first metal ion species and (ii) a second metal-ion salt including a second metal ion species, wherein the first and second metal ion species are different.19. The battery cell of claim 1, wherein the battery cell exhibits a charging potential of at least about 4.3V.20. The battery cell of claim 1, wherein the anode particles are composite particles that comprise silicon.21. The battery cell of claim 1, wherein the anode electrode further comprises a water-soluble binder.