Low Voltage Charge/Discharge Behavior of Manganese Hexacyanoferrate

Masamitsu Takachi,Yutaka Moritomo,Takayuki Shibata

doi:10.3390/batteries3010007

Masamitsu Takachi, Yutaka Moritomo + Show 1 more

Open Access

https://doi.org/10.3390/batteries3010007

Copy DOI

Abstract

Recently, Prussian blue analogues (PBAs) have been reported to exhibit a low voltage charge/discharge behavior with high capacity (300–545 mAh/g) in lithium-ion secondary batteries (LIBs) [...]

Highlights

We carefully investigated the low voltage charge/discharge behavior observed in the thin film of Na1.34 Mn[Fe(CN)6 ]0.84 ·3.4H2 O by means of ex situ synchrotron radiation X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) at Fe and Mn K edges without air exposure
Our careful experiment revealed that the low voltage charge/discharge behavior has no relation to the Mn-Prussian blue and its analogues (PBAs) itself, but is ascribed to the byproducts, i.e., Fe and Mn metals, made by the reduction process of the Mn-PBA
The diffraction peaks due to Mn-PBA do not appear even in the 1st charged film. These observations indicate that the low voltage charge/discharge behavior has no relation to the Mn-PBA itself, but should be ascribed to the byproducts

Summary

Introduction

Nanoporous materials [1] have been attracting increasing interest due to their functionalities for lithium-ion secondary batteries (LIBs), hydrogen storage, molecular storage, and gas separation.Among nanoporous materials, transition metal hexacyanoferrates or Prussian blue and its analogues (PBAs), denoted as A x M[Fe(CN)6 ]y (A and M, are the alkali and transition metals, respectively), are most intensively investigated for LIBs [2,3,4,5,6,7,8] and sodium-ion secondary batteries (SIBs) [9,10,11,12,13].The PBAs consist of three-dimensional cyano-bridged networks (jungle-gym type networks) of the transition metal, –M–NC–Fe–CN–M–, with periodic nano-cubes of 5 Å on each side [14,15]. Nanoporous materials [1] have been attracting increasing interest due to their functionalities for lithium-ion secondary batteries (LIBs), hydrogen storage, molecular storage, and gas separation. Transition metal hexacyanoferrates or Prussian blue and its analogues (PBAs), denoted as A x M[Fe(CN)6 ]y (A and M, are the alkali and transition metals, respectively), are most intensively investigated for LIBs [2,3,4,5,6,7,8] and sodium-ion secondary batteries (SIBs) [9,10,11,12,13]. Goodenough’s group [7] reported charge/discharge properties of the SIB cathodes in a K–M–Fe(CN) system (M = Mn, Fe, Co, Ni, Cu, Zn) even though their coulomb efficiency is poor. The coulomb efficiency is significantly improved in thin films of

Methods

Discussion

Conclusion