Activating C-Coordinated Iron of Iron Hexacyanoferrate for Zn Hybrid-Ion Batteries with 10 000-Cycle Lifespan and Superior Rate Capability

Qi Yang; Funian Mo; Zhuoxin Liu; Longtao Ma; Xinliang Li; Daliang Fang; Shimou Chen; Suojiang Zhang; Chunyi Zhi

doi:10.1002/adma.201901521

Activating C-Coordinated Iron of Iron Hexacyanoferrate for Zn Hybrid-Ion Batteries with 10 000-Cycle Lifespan and Superior Rate Capability

Adv Mater. 2019 Aug;31(32):e1901521. doi: 10.1002/adma.201901521. Epub 2019 Jun 13.

Authors

Qi Yang¹, Funian Mo¹, Zhuoxin Liu¹, Longtao Ma¹, Xinliang Li¹, Daliang Fang², Shimou Chen², Suojiang Zhang², Chunyi Zhi^{1

3}

Affiliations

¹ Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR, 999077, China.
² Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
³ Shenzhen Research Institute, City University of Hong Kong, Shenzhen, 518057, China.

PMID: 31192499
DOI: 10.1002/adma.201901521

Abstract

Prussian blue analogue (PBA)-type metal hexacyanoferrates are considered as significant cathodes for zinc batteries (ZBs). However, these PBA-type cathodes, such as cyanogroup iron hexacyanoferrate (FeHCF), suffer from ephemeral lifespan (≤1000 cycles), and inferior rate capability (1 A g^-1 ). This is because the redox active sites of multivalent iron (Fe(III/II)) can only be very limited activated and thus utilized. This is attributed to the spatial resistance caused by the compact cooperation interaction between Fe and the surrounded cyanogroup, and the inferior conductivity. Here, it is found that high-voltage scanning can effectively activate the C-coordinated Fe in FeHCF cathode in ZBs. Thanks to this activation, the Zn-FeHCF hybrid-ion battery achieves a record-breaking cycling performance of 5000 (82% capacity retention) and 10 000 cycles (73% capacity retention), respectively, together with a superior rate capability of maintaining 53.2% capacity at superhigh current density of 8 A g^-1 (≈97 C). The reversible distortion and recovery of the crystalline structure caused by the (de)insertion of zinc and lithium ions is revealed. It is believed that this work represents a substantial advance on PBA electrode materials and may essentially promote application of PBA materials.

Keywords: C-coordinated Fe; Prussian blue analogue; activation; ultralong lifespan; zinc hybrid-ion batteries.

Abstract

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