Current state of the art lithium ion batteries have reached a plateau in energy density. Next generation materials are becoming available and researched. There are two directions being pursued to achieve higher energy density. The first path is to use materials that have higher energy density than the ones currently used, for example, incorporating silicon into the anode or transitioning to lithium as the anode. A second direction is to use cathode materials that are electrochemically active at higher voltages. Lithium cobalt phosphate (LCP) is one example of a cathode material that operates at a higher voltage than state of the art materials (4.8 V vs Li). Pure LCP suffers from severe capacity fade due to structural degradation during cycling. Recently we have been able to increase the cycle life of LCP by the introduction of elemental substitution of iron, chromium and silicon. The major challenge now is that conventional electrolytes are not stable at the elevated voltages at which LCP cycles. The electrolytes must not only be stable at high voltages but also at low voltage if graphite is used as the anode material. Generally, when the oxidative stability voltage of the electrolyte increases, the reductive stability voltage increases causing problems on the anode. The progress of electrolyte development for LCP batteries will be discussed.