Slight Zinc Doping by an Ultrafast Electrodeposition Process Boosts the Cycling Performance of Layered Double Hydroxides for Ultralong-Life-Span Supercapacitors

Abstract

Layered double hydroxides (LDHs) have attracted much attention in supercapacitors because of the high specific surface area and theoretical capacitance. However, the bad cycling stability has always been their Achilles’ heel that restrains their further application. In this paper, a small amount of unactive and single-valence element zinc, which has no contribution to the capacitance of electrodes, was first doped into NiCo-LDHs through two consecutive electrodeposition processes only within 30 min. With a polyaniline (PANI) nanolayer as the interlayer, an ultrathin NiCoZn-LDH nanoplate network was well-anchored on the carbon cloth surface. The slight Zn2+ doping dramatically enhanced the cycling performance of LDHs with little capacitance decay. Zn2+ doping enhanced the cyclic structural stability of NiCoZn-LDHs, while the PANI layer strengthened the interface interaction between LDHs and the current collector. By controlling the doping content of Zn2+ at 2.9%, the composite electrode achieved the best performance with a high specific capacitance of 1749 F g–1 and an ultralong life span with 89% capacitance retention after 40,000 charge–discharge cycles. This work offers a novel strategy to fast build LDH-based supercapacitors with both high specific capacitance and cycling performance.

Hierarchical Nanocages Assembled by NiCo-Layered Double Hydroxide Nanosheets for a High-Performance Hybrid Supercapacitor

“…The energy density and power density of the NiCo-LDH-210//CNF HSC device were sketched from the Ragone plots, as shown in Figure 8e. Encouragingly, the HSC device can store a maximum energy density of 57.3 W h kg −1 at a power density of 1600 W kg −1 , and this remained at 35.6 W h kg −1 at 8000 W kg −1 , which are much superior to those of recently reported LDH-based HSC devices, such as ZnCo 2 O 4 @Ni-Al LDH//AC (50.1 W h kg −1 at 3400 W kg −1 ), 46 HA-NiCo-LDH//AC (44.9 W h kg −1 at 348 W kg −1 ), 47 NCZ-LDH-100@PANI//AC (37.2 W h kg −1 at 362 W kg −1 ), 48 NF@F-NCCH12//AC (35.3 W h kg −1 at 375 W kg −1 ), 49 NiCo-LDH/10//CNT (36.1 W h kg −1 at 649 W kg −1 ), 50 Cu 1.65 Co 1 -LDH//Cu 1.65 Co 1 -LDH (52.89 W h kg −1 at 1215 W kg −1 ), 51 and NiCo LDH@rGO (35 W h kg −1 at 750 W kg −1 ), 52 It also surpasses many cobalt-based compound HSC devices, such as EO-Co-MOF@CoNiO 2 /CC//AC (27.4 W h kg −1 at 750 W kg −1 ) 53 and Co 3 O 4 -NSs/CNTs-5%//rGO (37.2 W h kg −1 at 160.2 W kg −1 ). 54 Figure 8f presents the cyclic stability of the NiCo-LDH-210//CNF HSC device at a current density of 4 A g −1 .…”

Ternary layered double hydroxide cathode materials for electrochemical energy storage: a review and perspective

“…The existence of both Zn 2+ and the PANI nanolayer matter a lot to the cycling performance, where zinc promotes the intrinsic cycling structural stability and the PANI nanolayer prevents LDHs from exfoliation and dissolution. 180 This method provides a new strategy and inspiration for the rapid preparation of SCs with high capacitance and long life in a time-saving and controllable way.…”

“…(f) Schematic illustration of the preparation steps of NCZ-LDHs@PAN. (g) Ragone plot of the ASC and other reported hybrid devices for comparison and (h) the cycling performance of the NCZ-LDH-100@PANI//AC ASC 180. Copyright 2021, American Chemical Society.…”

A VO3−-induced S2−-exchange strategy to controllably construct a sub-nano-sulfide-functionalized layered double hydroxide for an enhanced supercapacitor performance

“…21 Numerous effective strategies have been proposed to guide the design and function of LDH materials for an enhanced supercapacitor performance, and these can be divided into two categories. [22][23][24] One strategy is morphology engineering for the construction of LDH materials with various morphologies, such as nano-rods, [25][26][27][28][29] nano-plates, [30][31][32] nano-spheres [33][34][35] and nano-polyhedra, 36 and to build the hierarchical porous structure of mesopores and micropores in the LDH materials to create deep diffusion channels for the electrolyte. This is particularly applicable for nanomaterials with hollow structures, which can not only provide rich active centers for enhanced capacitance but also provide sufficient space to alleviate the volume effect in the charging and discharging process.…”