Electronic structure of activation-induced layered structure in NiCoAl for energy storage application
Thanigai Arul Kumaravelu1*, Anbalagan Ramakrishnan2, Ying-Rui Lu3, Jeng-Lung Chen3, Sinn-wen Chen2,4, Chao-Hung Du1, Mei-Yu Chen1, Ping-Hung Yeh1, K. Asokan5,6, Ching-Hsiang Chen7, Chung-Li Dong1
1Department of Physics, Tamkang University, New Taipei City 251301, Taiwan
2Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
3National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
4High Entropy Materials Center, National Tsing Hua University, Hsinchu, Taiwan
5Inter-University Accelerator Centre, New Delhi 110 067, India
6Department of Physics & Centre for Interdisciplinary Research, University of Petroleum and Energy Studies, Uttarakhand 248007, India
7CL Technology Co., Ltd., New Taipei, Taiwan
* Presenter:Thanigai Arul Kumaravelu, email:thanigaiarul.k@gmail.com
Electronic and local atomic structures of self-supported layered double hydroxides (LDHs) on alloys are scarce. The LDHs can be achieved by a surface activation capable to improve electrochemical interactions, ion diffusivity, and swift kinetics of ions/electrons to aid in the formation of self-supported LDHs on the alloys. In this work, Ni ions were substituted in CoAl alloys that were prepared by arc melting route, and further, the prepared alloys were activated by KOH electrolyte responsible for the modulation of atomic configuration and generation of abundant active sites that transform the alloy surface into a layered structure of CoOOH/Co(OH)2. The alloys were characterized by XRD, Raman depth mapping, SEM, electrochemical measurement, cyclic stability, and X-ray Absorption Spectroscopy. The activated Ni10Co85Al5 has a high volumetric capacitance in comparison with the unactivated one. The analytical results demonstrate that high charge transfer by Co than by Ni and the alteration of local atomic structures facilitate superior electrochemical charge storage in Ni10Co85Al5 and this work provides a new strategy for designing of LDHs.


Keywords: Activation, Layered structure, Electronic structure, Atomic structure, Electrochemical charge storage