Selective control of composition in Prussian white for enhanced material properties

DOI: 10.1021/acs.chemmater.9b01494

Authors: William R. Brant (Uppsala University) , Ronnie Mogensen (Uppsala University) , Simon Colbin (Uppsala University) , Dickson O. Ojwang (Uppsala University) , Siegbert Schmid (The University of Sydney) , Lennart Häggström (Uppsala University) , Tore Ericsson (Uppsala University) , Aleksander Jaworski (Stockholm University) , Andrew J. Pell (Stockholm University) , Reza Younesi (Uppsala University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry Of Materials

State: Published (Approved)
Published: August 2019
Diamond Proposal Number(s): 17901

Abstract: Sodium ion batteries based on Prussian blue analogues (PBAs) are ideal for large scale energy storage applications due to the ability to meet the huge volumes and low costs required. For Na2-xFe[Fe(CN)6]1-y.zH2O realising its commercial potential means fine control of the concentration of sodium, Fe(CN)6 vacancies and water content. To date, there is a huge variation in the literature of composition leading to variable electrochemical performance. In this work, we break down the synthesis of Prussian blue analogous (PBAs) into three steps for controlling the sodium, vacancy and water content via an inexpen-sive, scalable synthesis method. We produce rhombohedral Prussian white Na1.88(5)Fe[Fe(CN)6].0.18(9)H2O with an initial capacity of 158 mAhg-1 retaining 90% capacity after 50 cycles. Subsequent characterisation revealed that the increased polarisation on the 3 V plateau is coincident with a phase transition and reduced utilisation of the high spin Fe(III)/Fe(II) redox couple. This reveals a clear target for subsequent improvements of the material to boost long term cycling stability. These results will be of great interest for the myriad of applications PBAs are suited towards such as catalysis, magnetism, electrochromics and gas sorption.

Diamond Keywords: Batteries; Sodium-ion

Subject Areas: Materials, Chemistry, Energy


Instruments: I09-Surface and Interface Structural Analysis

Other Facilities: DESY

Added On: 02/09/2019 11:24

Discipline Tags:

Energy Storage Energy Physical Chemistry Energy Materials Chemistry Materials Science Chemical Engineering Engineering & Technology

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Near Edge X-ray Absorption Fine Structures (NEXAFS)