Internal Electric Field Built on Heterointerface of H₂TiO₃/H₄Ti₅O₁₂ Hybrid Enabling Promoted Li Extraction...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Titanium-based oxides like H₂TiO₃ and H₄Ti₅O₁₂ are promising Li-ion sieve (LIS) materials for lithium extraction.
• Current LIS materials show poor performance under neutral conditions due to insufficient driving force for Li exchange.

Purpose of the Study:

• To develop a hybrid H₂TiO₃/H₄Ti₅O₁₂ material with enhanced Li exchange capacity, particularly under neutral conditions.
• To investigate the role of internal electric fields in improving Li extraction kinetics.

Main Methods:

• A facile one-step solid-state method was used to synthesize the H₂TiO₃/H₄Ti₅O₁₂ hybrid.
• The material's Li exchange performance was evaluated under alkaline and neutral conditions.
• The formation of an internal electric field at phase boundaries was analyzed.

Main Results:

• The H₂TiO₃/H₄Ti₅O₁₂ hybrid exhibited high Li exchange capacities of 42.43 mg g⁻¹ (alkaline) and 20.50 mg g⁻¹ (neutral).
• The material achieved high Li extraction rates of 5.30 mg g⁻¹ h⁻¹ (alkaline) and 2.05 mg g⁻¹ h⁻¹ (neutral).
• An internal electric field generated at the phase interface significantly boosted Li⁺ transport and extraction kinetics.

Conclusions:

• The developed H₂TiO₃/H₄Ti₅O₁₂ hybrid demonstrates superior Li extraction performance, especially under neutral conditions.
• The internal electric field is an effective strategy to enhance Li-ion sieve performance.
• This work offers a novel approach for improving lithium resource extraction.