Flower-like Y-doped α-Ni(OH)2/graphene heterostructure as advanced electrodes for high performance supercapacitor

Rare Earth‐Based Nanomaterials for Supercapacitors: Preparation, Structure Engineering and Application

“…The incorporation of Y induces the crystal phase of Ni(OH) 2 from β‐ to α‐phase, resulting in larger interlayer space of Ni(OH) 2 (from pristine 4.64 Å to optimal 7.45 Å), which is beneficial to the contact and diffusion of electrolyte ions. As shown in Figure 6, as‐prepared Y‐doped α‐Ni(OH) 2 /graphene had a high specific capacitance of 822.3 C g −1 at 1 A g −1 and 562.4 C g −1 at 20 A g −1 in 6 m KOH electrolyte [187] . The excellent electrochemical performance of this compound is inseparable from the following characteristics: (1) the addition of Y 3+ ions reduces the charge transfer resistance of the pristine Ni(OH) 2 , thereby ensuring the faster charge transfer kinetics; (2) the introduction of Y 3+ ions and graphene favor the stabilization of the crystal structure of Ni(OH) 2 , the improvement of specific surface area, and the formation of open ion channels, thus leading to better electroactivity.…”

“…TMHs are becoming more and more sought after because of their high theoretical specific capacitance, stable structure, ample active sites, and compatibility with electrolytes [147,184] . Up to now, parallel to TMOs, RE ion doping or the introduction of REOs can also improve the capacitive properties of TMHs such as Y‐doped Ni(OH) 2 [185–187] . Especially, He and co‐workers improved the specific capacity of Ni(OH) 2 nanocrystals via Y 3+ ions doping.…”

“…[147,184] Up to now, parallel to TMOs, RE ion doping or the introduction of REOs can also improve the capacitive properties of TMHs such as Y-doped Ni(OH) 2 . [185][186][187] Especially, He and co-workers improved the specific capacity of Ni(OH) 2 nanocrystals via Y 3 + ions doping. The Y-doped Ni(OH) 2 obtained by hydrothermal method reached specific capacitance of 735.46 C g À 1 , which is superior to that of pristine samples (279.7 C g À 1 ).…”

“…As shown in Figure 6, as-prepared Y-doped α-Ni(OH) 2 /graphene had a high specific capacitance of 822.3 C g À 1 at 1 A g À 1 and 562.4 C g À 1 at 20 A g À 1 in 6 m KOH electrolyte. [187] The excellent electrochemical performance of this compound is inseparable from the following characteristics: In order to further improve the capacitance performance of TMHs, another method based on the synergistic effect between the components was provided to use CPs and REOs to modify TMHs. Das et al reported the capacitive performance of CeO 2 / NiV-layered double hydroxide (CeO 2 /NiV-LDH) obtained by hydrothermal route.…”

A binary composite La(OH)3@Ni(OH)2 nanomaterial on carboxyl graphene for an efficient hybrid supercapacitor electrode

“…8 To address these issues, researchers have attempted to dope the material with suitably selected cations such as Ag, Mn, Co, Zn, Al and Y to induce articial defects. [9][10][11][12][13][14][15] Among these, the incorporation of Ag dopants into Ni(OH) 2 can greatly increase its electrical conductivity due to the increase in chemical activity of the Ag dopants, resulting in the improved the charge transport mechanism and the decrease of resistivity. Mn doping in Ni(OH) 2 would effectively improve its electrochemical stability by reducing the crystallite size of Ni(OH) 2 and forming Mn 2+ ions, thereby facilitating the transfer of ions and electrons to reduce the reaction barriers of electrochemical processes.…”