KTi₈O_16.5 Nanobelt Array with the Zero Strain Property for High-Performance Lithium-Ion Batteries with Enhanced Capacity and Rate Capability

Lithium-ion batteries (LIBs) with Li4Ti5O12 as the anode possesses good rate capability and high safety but faces a great challenge of energy density improvement. Here, a kind of potassium titanate with the morphology of a thin nanobelt and uniform distributed array (N-KTi8O16.5) has been synthesized to address it. Benefiting from the large lattice spacing of 1.01 nm and thin nanobelt thickness, the kinetics of Li+ ion transport and the Li+ ion storage capability were improved. Combined with the pseudo-capacitance effect, N-KTi8O16.5 delivered a high initial capacity of 871.2 mA h g–1 and a high residual capacity of 473.8 mA h g–1 after 350 cycles. The capacity at a current density of 5 A g–1 was ∼150 mA h g–1, and this enabled it to climb back to ∼600 mA h g–1 at 0.2 A g–1 after a gradually increasing rate capability test. This strategy provides a potential avenue to achieving high-performance LIBs with enhanced capacity and rate capability using alkali metal titanate as the anode.