Angstrom-Confined Ti₀.₈₇O₂ Ion Sieve

Zn-selective, dendrite-free

An interfacial layer based on unilamellar Ti₀.₈₇O₂ nanosheets that exploits atomic Ti vacancies and interlayer spacing to selectively transport Zn²⁺ while blocking water and anions, fundamentally suppressing dendrites and side reactions in aqueous zinc batteries.

Peng, Xing · Ye, Caichao · Honglan, Huang · Hou, Zhen · Fu, Yongsheng · Chen, Mingzhe · Hu, Linfeng · Xiong, Pan · Wang, Guoxiu · Zhu, Junwu

Advanced Materials 2026

Specifications

Cycle life
{'zh': '>5000', 'en': '>5000'} h
Cycle life
{'zh': '>4000', 'en': '>4000'} h
Capacity retention
{'zh': '85.4', 'en': '85.4'} %
Ti vacancy size
{'zh': '3.0 × 3.8', 'en': '3.0 × 3.8'} Å
Interlayer spacing
{'zh': '3.5', 'en': '3.5'} Å
Zn²⁺ ionic radius
{'zh': '1.5', 'en': '1.5'} Å
H₂O molecule size
{'zh': '4.0', 'en': '4.0'} Å
SO₄²⁻ ion size
{'zh': '5.9', 'en': '5.9'} Å

Advantages

Zn²⁺ selective

Atomic Ti vacancies (~3.0×3.8 Å) and interlayer spacing (~3.5 Å) allow only Zn²⁺ (~1.5 Å) to pass, blocking H₂O (~4.0 Å) and SO₄²⁻ (~5.9 Å), thereby suppressing side reactions.

Stable cycling

Symmetric cells cycle stably for over 5000 h at 1 mA cm⁻² and 4000 h at 5 mA cm⁻² without dendrite growth.

Pouch cell demonstrated

Ah-level pouch cell retains 85.4% capacity after 300 cycles at 3 A g⁻¹, demonstrating scalability.

Applications