Abstract Li 4 Ti 5 O 12 typically shows a flat charge/discharge curve, which usually leads to difficulty in the voltage‐based state of charge (SOC) estimation. In this study, a facile quench‐assisted solid‐state method is used to prepare a highly crystalline binary Li 4 Ti 5 O 12 ‐Li 2 Ti 3 O 7 nanocomposite. While Li 4 Ti 5 O 12 exhibits a sudden voltage rise/drop near the end of its charge/discharge curve, this binary nanocomposite has a tunable sloped voltage profile. The nanocomposite exhibits a unique lamellar morphology consisting of interconnected nanograins of ≈20 nm size with a hierarchical nanoporous structure, contributing to an enhanced rate capability with a capacity of 128 mA h g −1 at a high C‐rate of 10 C, and excellent cycling stability.