TY - JOUR
T1 - Soft-chemical topotactic pathway to (001)-faceted hollandite K-Fe-Ti oxides with accelerated Li+ migration
AU - Wang, Xing
AU - Che, Ling
AU - Li, Zihao
AU - Chen, Zhigao
AU - Kong, Xingang
AU - Zhang, Kun
AU - Xie, Keyu
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2026/1/1
Y1 - 2026/1/1
N2 - Tunnel-structured hollandite-type oxides hold promise for lithium-ion storage owing to their structural stability and zero-strain characteristics, yet their electrochemical performance is severely constrained by facet-dependent ion transport. Conventional hydrothermal and solid-state routes predominantly expose the (010) facet, where closed lattice channels impose high Li+ migration barriers and sluggish kinetics. Here, we develop a soft-chemical topotactic transformation strategy that exploits an iron-containing layered titanate precursor to achieve crystallographically inherited hollandite architectures with preferentially exposed (001) facets. This approach contrasts sharply with strong-acid treatments that yield rod-like (010)-faceted products, thereby providing a direct structural and electrochemical comparison. First-principles calculations reveal that the (001) facet reduces the Li+ migration barrier from 0.22 to 0.06 eV, while electrochemical measurements reveal that KFTO with exposed (001) facet exhibits a higher coefficient of 2.23 × 10−15 cm2 S−1 than that of KFTO with exposed (001) facet (1.11 × 10−16 cm2 S−1). By bridging facet engineering with a controllable synthesis pathway, this work establishes a paradigm for tailoring ion transport in tunnel-structured oxides, offering a generalizable route toward high-performance electrodes for fast-charging and durable energy storage.
AB - Tunnel-structured hollandite-type oxides hold promise for lithium-ion storage owing to their structural stability and zero-strain characteristics, yet their electrochemical performance is severely constrained by facet-dependent ion transport. Conventional hydrothermal and solid-state routes predominantly expose the (010) facet, where closed lattice channels impose high Li+ migration barriers and sluggish kinetics. Here, we develop a soft-chemical topotactic transformation strategy that exploits an iron-containing layered titanate precursor to achieve crystallographically inherited hollandite architectures with preferentially exposed (001) facets. This approach contrasts sharply with strong-acid treatments that yield rod-like (010)-faceted products, thereby providing a direct structural and electrochemical comparison. First-principles calculations reveal that the (001) facet reduces the Li+ migration barrier from 0.22 to 0.06 eV, while electrochemical measurements reveal that KFTO with exposed (001) facet exhibits a higher coefficient of 2.23 × 10−15 cm2 S−1 than that of KFTO with exposed (001) facet (1.11 × 10−16 cm2 S−1). By bridging facet engineering with a controllable synthesis pathway, this work establishes a paradigm for tailoring ion transport in tunnel-structured oxides, offering a generalizable route toward high-performance electrodes for fast-charging and durable energy storage.
KW - Facet engineering
KW - Hollandite-type oxides
KW - Ion transport kinetics
KW - Topotactic synthesis
KW - Tunable tunnel K occupancy
UR - https://www.scopus.com/pages/publications/105024846899
U2 - 10.1016/j.cej.2025.171863
DO - 10.1016/j.cej.2025.171863
M3 - 文章
AN - SCOPUS:105024846899
SN - 1385-8947
VL - 527
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 171863
ER -