Partial Atomic Disordered Ti₂Nb₁₀O₂₉ _-x Induced by Joule Thermal Shock for Superior Lithium-Ion Storage.

Abstract

Nb₂O₅ is a promising anode for high-power lithium-ion battery, but its relatively dense atomic packing limits Li⁺ migration capacity exertion. Ti₂Nb₁₀O₂₉ with Wadsley-Roth phase with more open crystal structure is considered a promising candidate. However, Ti/Nb atoms prefer to form an ordered arrangement to maintain local charge balance, resulting insufficient Li⁺ migration and suppressing high-rate performance. Herein, defective Ti₂Nb₁₀O_29- _x anode with partial disordered Ti/Nb arrangement is developed by employing an amorphous precursor combined with Joule thermal shock. The random dispersion of Ti and Nb within the amorphous precursor is maintained to a certain extent during ultra-fast Joule thermal heating (≈500°C s^-1) and quenching (≈250°C s^-1). Compared to traditional Ti₂Nb₁₀O₂₉, the Li⁺ diffusion coefficient and electronic conductivity of Ti/Nb-disordered Ti₂Nb₁₀O_29- _x are enhanced by tenfold and four orders of magnitude, respectively. As the anode of lithium-ion batteries, the optimal Ti₂Nb₁₀O_29- _x shows an ultra-high capacity of 353 mAh g^-1 and an excellent rate capability of 112 mAh g^-1 at 150 C, an ultra-long cycling lifespan of 5000 cycles, and a wide operating temperature range from 80°C to -40°C. The performance leap caused by the disordered structure may provide new paradigm for battery materials.