Chemical Sciences and Engineering Division, Argonne National Laboratory , 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
ACS Appl Mater Interfaces. 2017 Feb 8;9(5):4391-4396. doi: 10.1021/acsami.6b14341. Epub 2017 Jan 20.
Transition metal-containing polyanion compounds are attractive for use as cathode materials in sodium-ion batteries (SIB) because they possess elevated higher intrinsic electrochemical potentials versus oxide analogs given the same M redox couple, which leads to higher energy densities. NaMPO (M = transition metal) compounds have a driving force to form into the electrochemically inactive maricite phase when using conventional methods. Herein we report on the synthesis of a NaCoPO (NCP) polymorph ("Red"-phase) by a microwave-assisted solvothermal process at 200 °C using tetraethylene glycol as the solvent. Ex situ XRD, XANES, and electrochemical data are used to determine the reversibility of the Co redox center.
含过渡金属的多阴离子化合物因其相对于相同 M 氧化还原对的氧化物类似物具有更高的固有电化学势，可用作钠离子电池 (SIB) 的阴极材料，从而具有更高的能量密度。NaMPO（M = 过渡金属）化合物在使用常规方法时具有形成电化学惰性白磷铁矿相的驱动力。在此，我们报告了一种通过微波辅助溶剂热法在 200°C 下使用四乙二醇作为溶剂合成 NaCoPO（NCP）多晶型物（“Red”-相）的方法。利用原位 XRD、XANES 和电化学数据来确定 Co 氧化还原中心的可逆性。
