skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Unraveling the formation mechanism of NaCoPO4 polymorphs

Journal Article · · Journal of Solid State Chemistry
 [1];  [1];  [1];  [2];  [1]
  1. Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore (India)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
+ Show Author Affiliations

Phosphate compounds are one of the attractive classes of cathodes for their potential application in rechargeable Na-ion batteries (NIBs) due to their high insertion voltages and stabilities. Unlike olivine-LiMPO4 (M = Fe, Mn, Co, Ni) cathodes, maricite-NaMPO4 phases are electrochemically inactive due to lack of sodium diffusion channels. Interestingly, cobalt bearing compounds exhibit rich polymorphism (α-, β-, ABW- and Red-NaCoPO4). However, the preparation of NaCoPO4 single phases is challenging due to their closer enthalpies of formation. In this study, we have attempted to understand the formation mechanism of NaCoPO4 polymorphs during solid state reaction using two different cobalt precursors (Co(OH)2 and CoCO3). The temperature dependent in-situ powder X-ray Diffraction (PXRD) studies showed the formation of β-NaCoPO4 at a much lower temperature compared to the one reported in the literature, whilst we have discovered a new high temperature polymorph gamma-NaCoPO4. The choice of precursors was also found to be important for the preparation of ABW-NaCoPO4, i.e., the rapid decomposition of Co(OH)2 has resulted in its formation whilst the high stability of CoCO3 prohibited the same. The order of the formation of the NaCoPO4 polymorphs during heating was found to be ABW→β→α →$$\gamma$$. During normal cooling, gamma-NaCoPO4 transformed primarily into alpha-polymorph whilst quenching in liquid N-2 resulted in the formation of β-NaCoPO4 The as-synthesized beta- and ABW-NaCoPO4 phases exhibited high sodium (de)-intercalation voltages (similar to 4.2 and 4.5 V vs. Na+/Na0, respectively), albeit with limited reversible capacities. This study is expected to open new avenues to harvest metastable polymorphs based on other transition metals (Fe, Mn and Ni).

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Organization:
Government of India - Department of Science and Technology; USDOE
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1840566
Journal Information:
Journal of Solid State Chemistry, Vol. 293; ISSN 0022-4596
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (38)

Comparison of electrochemical performances of olivine NaFePO 4 in sodium-ion batteries and olivine LiFePO 4 in lithium-ion batteries journal January 2013
Generalized Gradient Approximation Made Simple journal October 1996
A comprehensive review of sodium layered oxides: powerful cathodes for Na-ion batteries journal January 2015
A molecular dynamics method for simulations in the canonical ensemble journal June 1984
Electrochemistry and Solid‐State Chemistry of NaMeO 2 (Me = 3d Transition Metals) journal June 2018
Projector augmented-wave method journal December 1994
Microwave-Assisted Solvothermal Synthesis of Three Polymorphs of LiCoPO 4 and Their Electrochemical Properties journal August 2015
Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set journal July 1996
Thermal expansion of AlN, sapphire, and silicon journal March 1974
Crystal structure and magnetic ordering in magnetoelectric KNiPO 4 investigated by means of X-ray and neutron diffraction journal January 1994
Layered Oxide Cathodes for Sodium-Ion Batteries: Phase Transition, Air Stability, and Performance journal November 2017
In Situ Growth of MOF-Derived NaCoPO 4 @Carbon for Asymmetric Supercapacitive and Water Oxidation Electrocatalytic Performance journal December 2019
Electrochemical Performances of Maricite NaFePO4/C as cathode material for Sodium-Ion and Lithium-Ion Batteries journal April 2017
From ultrasoft pseudopotentials to the projector augmented-wave method journal January 1999
Coordination tuning of cobalt phosphates towards efficient water oxidation catalyst journal September 2015
Structural chemistry of NaCoPO 4 journal June 1996
Magnetoelectricity in the Structurally Chiral and Polar Antiferromagnet β-NaCoPO 4 journal March 2015
Canonical dynamics: Equilibrium phase-space distributions journal March 1985
Syntheses and Characterizations of Chiral Tetrahedral Cobalt Phosphates with Zeolite ABW and Related Frameworks journal March 1997
Microwave-Assisted Synthesis of NaCoPO 4 Red-Phase and Initial Characterization as High Voltage Cathode for Sodium-Ion Batteries journal January 2017
Crystal Structures and Crystal Chemistry of AgXPO4(X=Be, Zn) journal November 1998
Optical and dielectric properties of NaCoPO 4 in the three phases α, β and γ journal January 2019
Ab initiomolecular dynamics for liquid metals journal January 1993
Synthesis and electrochemical performances of maricite-NaMPO 4 (M = Ni, Co, Mn) electrodes for hybrid supercapacitors journal January 2014
Unexpected discovery of low-cost maricite NaFePO 4 as a high-performance electrode for Na-ion batteries journal January 2015
Crystal structures of the three forms of CsZnPO4 journal July 1986
From Lithium-Ion to Sodium-Ion Batteries: Advantages, Challenges, and Surprises journal November 2017
A unified formulation of the constant temperature molecular dynamics methods journal July 1984
Topochemical Synthesis of Sodium Metal Phosphate Olivines for Sodium-Ion Batteries journal August 2011
Synthesis, Crystal Structure, and Magnetic Properties of a New Polymorphic Sodium Cobalt Phosphate with Trigonal Bipyramidal Co2+and a Tunnel Structure journal March 1997
1D/2D Cobalt‐Based Nanohybrids as Electrocatalysts for Hydrogen Generation journal April 2020
A new LiCoPO4 polymorph via low temperature synthesis journal January 2013
Phospho-olivines as Positive-Electrode Materials for Rechargeable Lithium Batteries journal April 1997
High-Performance Olivine NaFePO 4 Microsphere Cathode Synthesized by Aqueous Electrochemical Displacement Method for Sodium Ion Batteries journal August 2015
Energetics of cobalt phosphate frameworks: α, β, and red NaCoPO4 journal December 2006
Two-dimensional detector software: From real detector to idealised image or two-theta scan journal January 1996
Research Development on Sodium-Ion Batteries journal October 2014
Structural, vibrational spectroscopic, and electrical conduction mechanisms of α-NaCoPO4 compound journal January 2019

Similar Records

Elucidation of Anionic and Cationic Redox Reactions in a Prototype Sodium-Layered Oxide Cathode
Journal Article · Fri Oct 11 00:00:00 EDT 2019 · ACS Applied Materials and Interfaces · OSTI ID:1840566
+8 more
Sodium-ion Battery
Book · Sat Jan 01 00:00:00 EST 2022 · OSTI ID:1840566
+1 more
Exploring Oxygen Activity in the High Energy P2-Type Na0.78Ni0.23Mn0.69O2 Cathode Material for Na-Ion Batteries
Journal Article · Wed Mar 22 00:00:00 EDT 2017 · Journal of the American Chemical Society · OSTI ID:1840566
+5 more

Related Subjects

25 ENERGY STORAGE
NaCoPO4
Na-ion batteries
Polymorphs