Secondary lithium ion battery technology has made deliberate, incremental improvements over the past four decades, providing sufficient energy densities to sustain a significant mobile electronic device industry. Because current battery systems provide ∼100-150 km of driving distance per charge, ∼5-fold improvements are required to fully compete with internal combustion engines that provide >500 km range per tank. Despite expected improvements, the authors believe that lithium ion batteries are unlikely to replace combustion engines in fully electric vehicles. However, high fidelity and safe Li ion batteries can be used in full EVs plus range extenders (e.g., metal air batteries, generators with ICE or gas turbines). This perspective article describes advanced materials and directions that can take this technology further in terms of energy density, and aims at delineating realistic horizons for the next generations of Li ion batteries. This article concentrates on Li intercalation and Li alloying electrodes, relevant to the term Li ion batteries.