Selective synthesis and capacitive characteristics of CoNiAl three-component layered double hydroxide platelets

Abstract

CoNiAl three-component layered double hydroxides with tuneable chemical composition are synthesized by homogenous precipitation.CoNiAl LDH with a Co/Ni ratio of 5/1 displays a high specific capacitance (1124 F g À1 at 1 A g À1 ) and excellent long-term high-currentdensity performance (only 7% capacitance loss at 2 A g À1 after 1000 cycles).

True Meaning of Pseudocapacitors and Their Performance Metrics: Asymmetric versus Hybrid Supercapacitors

“…Some of the primary studies focused on the synthesis of single‐phase NiCo–LDH by changing the ratio of the nickel and cobalt precursors. [ 226,227 ] Recently many efforts have been taken to combine NiCo–LDH with different conducting materials such as graphene nanosheets, [ 228 ] reduced graphene oxide (rGO) [ 229 ] and V 4 C 3 MXene. [ 230 ] For example, Wang et al [ 230 ] prepared the composite electrodes by combining the NiCoAl–LDH and V 4 C 3 MXene in a single electrode to take the benefits of the battery‐type and capacitive‐type charge storage mechanism.…”

Recent development of metal hydroxides as electrode material of electrochemical capacitors

“…The CoN-iAl-LDH displayed the best capacitive performances when the molar ratio of Co/Ni reached 5. 173 The Co 0.55 Ni 0.13 Al 0.32 -LDH delivered more specic capacitance in 1 M KOH than in 1 M LiOH or NaOH. Increasing the concentration of KOH from 1 to 6 M, the specic capacitance was elevated from 644 to 1124 F g À1 at 1 A g À1 .…”

Urea-based hydrothermal synthesis of LiNi0.5Co0.2Mn0.3O2 cathode material for Li-ion battery

“…Urea had been used as fuel and chelating agent in the synthesis of doped LiCoO 2 [25], LiNi 0.5 Mn 1.5 O 4 spinel [26][27][28], lithium-rich cathode materials [29], and CoNiAl three-component layered double hydroxides [30]. The decomposition of urea releases CO 3 2− slowly at elevated temperature, and the following reaction can happen [31], which allows the precursor to precipitate:…”