Lithium titanate spinel (Li4Ti5O12) is used as an anode in state-of-the-art, commercial high-rate batteries because it reacts with lithium at 1.55 V vs. Li metal, thus avoiding the propensity for coulombically inefficient and potentially dangerous Li metal deposition on the anode under high charging current densities. However, Li4Ti5O12 has a low gravimetric and volumetric energy density due to its partial utilization of Ti 4+ redox centers, cycling between Li4Ti5O12 and Li7Ti5O12, and the necessity of nanosizing to enable high-rate operation. The nanoparticle morphology also presents challenges for material scale-up and processing. Alternatives to Li4Ti5O12 that retain the excellent safety properties but overcome some of the disadvantages could enable wider penetration of high-power battery energy storage.