Remarkable electrochemical lithium storage behaviour of two-dimensional ultrathin α-Ni(OH)₂ nanosheets

Abstract

The as-synthesized 2D ultrathin α-Ni(OH) 2 nanosheets show a reversible conversion-type electrochemical behaviour with a high activity toward lithium ion.Transition metal hydroxides are usually ignorable candidates for lithium storage application due to their possibile detrimental electrochemical behaviour. Here we focus on two-dimensional (2D) ultrathin α-Ni(OH)2 nanosheets and investigate their electrochemical mechanism as anode for lithium ion battery. The employed α-Ni(OH)2 nanosheets show a geometrically graphene-like 2D structure with an ultrahigh surface atomic ratio and large specific surface area of 189.57 m 2 g −1 . Electrochemical measurements demonstrate a reversible conversion-type electrochemical behaviour with a high activity toward lithium ion. When cycled at 100 mA g −1 current density, the ultrathin α-Ni(OH)2 nanosheets can deliver ultrahigh initial discharge and charge specific capacities of 1744.9 and 1364.6 mAh g −1 , with a high initial Coulombic efficiency (78.2%). Even at higher current density (200 mA g −1 ), the initial discharge and charge specific capacities is still retained at 1676.3 and 1301.4 mAh g −1 , respectively. The excellent lithium storage could be attributed to the large-area ultrathin 2D nanostructure, which can shorten lithium ion diffusion paths and provide large exposed surface for more lithium-insertion channels, making it a promising substitute for commercial graphite anode materials in lithium ion batteries.

One material, multiple functions: graphene/Ni(OH)2 thin films applied in batteries, electrochromism and sensors

“…It is clear to note the presence of two anodic and two cathodic peaks. As describe by others 52 53 , the reduction processes are related to both the formation of the solid electrolyte interface (SEI) film on the nanocomposite electrode (at −0.408 V, which consist of several lithium species as Li 2 CO 3 and RCO 2 Li) 54 , and the reduction of the Ni(OH) 2 to Ni (at −0.062 V, with consequent production of LiOH). In opposite, the anodic processes are attributed to the decomposition of the SEI (at 1.640 V) and the oxidation of the metallic Ni (at 1.374 V, with consequent decomposition of the LiOH).…”

Ni(OH)2‐Fe2O3/CNOs Ternary Nanocomposite Designed as an Anode with Complementary Properties for High‐Performance Li–Ion Battery

“…Two cathodic peaks at 0.71 V & 1.61 V and three anodic peaks at 1 V, 1.40 V & 2.4 V are observed in the CV of Ni(OH) 2 nanosheets which corresponds to the reduction of Ni 2+ to Ni and decomposition of LiOH at the electrode‐electrolyte interface respectively and vice versa in case of oxidation . In Fe 2 O 3 , two cathodic peaks at 0.89 V & 0.77 V and two anodic peaks at 1.64 V and 1.9 V are observed which correspond to the reduction of Fe 3+ to Fe 2+ and Fe 2+ to Fe and vice versa ,.…”

“…The solid electrolyte interface (SEI) layer formed on the surface of the electrode material and in the anodic region two peaks appear at 1.49 V and 2.2 V which corresponds to the oxidation of Fe to nanosheets which corresponds to the reduction of Ni 2 + to Ni and decomposition of LiOH at the electrode-electrolyte interface respectively and vice versa in case of oxidation. [11] In Fe 2 O 3 , two cathodic peaks at 0.89 V & 0.77 V and two anodic peaks at 1.64 V and 1.9 V are observed which correspond to the reduction of Fe 3 + to Fe 2 + and Fe 2 + to Fe and vice versa. [24,25] From the CV analysis of these samples it can be reiterated that the reduction and oxidation processes in the Ni(OH) 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 components of hybrid electrodes happens sequentially (with their maximal electrochemical redox activity at different potentials), which is accompanied by the sequential volume expansion and contraction in Ni(OH) 2 and Fe 2 O 3 components of the electrode.…”

“…Apart from the metal oxides, recently, metal hydroxides are also being investigated as electrode materials for the LIBs. It is hypothesized that hydroxyl group gives an additional reversible capacity by the formation of LiOH followed by Li 2 O at relatively lower voltages ,. However, these studies are scant and still at nascent level.…”

“…It is hypothesized that hydroxyl group gives an additional reversible capacity by the formation of LiOH followed by Li 2 O at relatively lower voltages. [11,12] However, these studies are scant and still at nascent level. More investigations of the lithium storage capabilities of these hydroxides are required to understand and improve their electrochemical performance in LIBs.…”