Evaluation of Metal Phosphide Nanocrystals as Anode Materials for Na-ion Batteries

Authors

  • Marc Walter ETH Zürich, Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, HCI H 139, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland; EMPA - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for thin films and photovoltaics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Maryna I. Bodnarchuk ETH Zürich, Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, HCI H 139, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland; EMPA - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for thin films and photovoltaics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Kostiantyn V. Kravchyk ETH Zürich, Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, HCI H 139, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland; EMPA - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for thin films and photovoltaics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Maksym V. Kovalenko ETH Zürich, Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, HCI H 139, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland; EMPA - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for thin films and photovoltaics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland. Maksy.Kovalenko@empa.ch mvkovalenko@ethz.ch

DOI:

https://doi.org/10.2533/chimia.2015.724

Keywords:

Anode materials, Li-ion batteries, Na-ion batteries, Nanocrystals, Synthesis

Abstract

Sodium-ion batteries (SIBs) are potential low-cost alternatives to lithium-ion batteries (LIBs) because of the much greater natural abundance of sodium salts. However, developing high-performance electrode materials for SIBs is a challenging task, especially due to the ?50% larger ionic radius of the Na+ ion compared to Li+, leading to vastly different electrochemical behavior. Metal phosphides such as FeP, CoP, NiP2, and CuP2 remain unexplored as electrode materials for SIBs, despite their high theoretical charge storage capacities of 900–1300 mAh g–1. Here we report on the synthesis of metal phosphide nanocrystals (NCs) and discuss their electrochemical properties as anode materials for SIBs, as well as for LIBs. We also compare the electrochemical characteristics of phosphides with their corresponding sulfides, using the environmentally benign iron compounds, FeP and FeS2, as a case study. We show that despite the appealing initial charge storage capacities of up to 1200 mAh g–1, enabled by effective nanosizing of the active electrode materials, further work toward optimization of the electrode/electrolyte pair is needed to improve the electrochemical performance upon cycling.

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Published

2015-12-16