Research progress of high-rate capacity layered double hydroxide supercapacitor materials

doi:10.11949/0438-1157.20201296

Abstract

Abstract:

Layered double hydroxides （LDHs） are two-dimensional layered materials composed of positively charged metal hydroxide laminates， negatively charged anions between the layers， and water molecules， which can store and release charge through the reversible oxidation-reduction reaction between hydroxide and oxyhydroxide. LDHs have the advantages of high theoretical capacity， adjustable morphology and composition， low cost， and easy large-scale preparation， and have become the supercapacitor electrode materials with increasing attraction in recent years. To date, the rate capacities of LDHs are far from the expectation due to the low activity associated with low intrinsic activity and small active surface area, and the slow charge transport kinetics arising from the poor intrinsic conductivity to hinder electron transfer and the narrow interlayer distance to impede ion diffusion. Various strategies have developed to increase the activity, e.g., by regulating compositions, amorphizating, nanostructuring and constructing hierarchical structures, and to facilitate the charge transport kinetics, e.g., by compositing with carbon, depositing/growing on conductive substrates, expanding interlayer distance, exfoliation-self-assembly. This review starts with the structural characteristics and energy storage mechanism of LDHs, and then summarizes the strategies for improving the rate capacities of LDHs. The up-to-date progress in achieving the high-rate capacity by matching electron transfer with ion diffusion is also included, which suggests a new avenue to explore the advanced LDHs for energy storage.

Key words: layered double hydroxides, supercapacitors, electrochemistry, rate capacity, kinetics, nanomaterials, electrode engineering

摘要：

层状双金属氢氧化物（LDHs）是由带正电荷的金属氢氧化物层板、层间带负电荷的阴离子和水分子组成的二维层状材料，可通过氢氧化物与羟基氧化物之间的可逆氧化还原反应存储与释放电荷，具有理论容量高、形貌与组分可调、成本低、易宏量制备等优点，成为近年来备受关注的超级电容器电极材料。超级电容材料在大电流密度下的比容量与其应用潜力密切相关，研究者们通过材料设计及电极工程，探索了多种提升LDHs倍率容量（即不同电流密度下的容量）的方法与技术，但至今LDHs的实际储能性能仍然远低于预期。简述了LDHs的结构、储能机理与面临的挑战，从增加反应活性、促进电荷传输动力学的角度归纳总结了提升LDHs倍率容量的研究进展，探讨了通过匹配电子传输和离子输运能力进一步提升LDHs倍率容量的新思路。

关键词: 层状双金属氢氧化物, 超级电容器, 电化学, 倍率容量, 动力学, 纳米材料, 电极工程

CLC Number:

TQ 152

Jie ZHAO,Yue GUO,Zhen SHEN,Lijun YANG,Qiang WU,Xizhang WANG,Zheng HU. Research progress of high-rate capacity layered double hydroxide supercapacitor materials[J]. CIESC Journal, 2020, 71(11): 4851-4872.

赵杰,郭月,沈桢,杨立军,吴强,王喜章,胡征. 高倍率容量层状双金属氢氧化物超级电容材料的研究进展[J]. 化工学报, 2020, 71(11): 4851-4872.

Figures/Tables 16

Fig.1 Schematic illustration of LDHs structure

Fig.2 The equations and schematic illustration of electrochemical energy storage for NiCo-LDH in alkaline electrolyte

Fig.3 The strategies for enhancing the rate capacity of LDHs

Fig.4 Ragone plot for various electrical energy storage devices[126](performances of supercapacitors in Ref. [33-34,46,93,97,106,109,120-123,125] are also provided for comparison, the time constants of the devices are marked in the figure)

Fig.5 Characterization of the monolayer NiTi-LDH nanosheets[36]: TEM image (a); HRTEM image (b); AFM image(c) and the corresponding height profiles (d) (profiles of 1—3 in Fig.(d) correspond to the nanosheets of 1—3 in Fig. (c))

Fig.6 Hierarchical NiAl-LDH and rate capacities[39]: schematic preparation (a), core-shell structure[(b),(c)], yolk-shell structure[(d),(e)], hollow structure[(f),(g)], nanoparticles (h), rate capacities (i)

Fig.7 Influence of hierarchical structure on rate capacity of the CoAl-LDH nanosheet array[43]: schematic diagram of P-CO3-LDH and H-CO3-LDH (a), rate capacities (b) (performance of H-OH-LDH in Fig. (b) is provided for reference)

Fig.8 Electrochemical performances of the CoAl-LDH and the CoAl-LDH/CNTs composite[46]: schematic preparation of the CoAl-LDH/CNTs composite (a), electrochemical impedance spectra (b) (Rs is the intrinsic Ohmic resistance, Rct is the charge transfer resistance）, rate capacities(c) ( in Fig. (b)，(c) , the data of CNTs are also presented for reference)

Fig.9 Electrochemical performances of the NiAl-LDH and the NiAl-LDH/rGO composite[58]: schematic preparation of the NiAl-LDH/rGO composite (a), electrochemical impedance spectra (b), rate capacities at 3.57—17.86 A·g-1 (c)

Fig.10 Electrochemical performances of CC-LDH and CC-NC-LDH electrodes[93]: schematic preparation of the CC-NC-LDH electrode (a), electrochemical impedance spectra (b), rate capacities (c) (the performance of NiCo-LDH in Fig.(c) is also presented for reference)

Fig.11 Schematic preparation of the NiCo-LDH/NF electrode and the hybrid supercapacitors[97]

Fig.12 Influence of interlayer distance on rate capacity of CoAl-LDH[109]: schematic regulation of the interlayer distance (a), electrochemical impedance spectra (b), rate capacities at 1—32 A·g-1(c) ( DS- is dodecyl sulfate anion in Ref.[109])

Fig.13 Schematic preparation of the LDHs-based composites by exfoliation-self-assembly method: CoAl-LDH/rGO film (a) [120],CoNi-LDH/PEDOT:PSS composite (b) [122]

Fig.14 The regulation of interlayer distance of NiAl-LDH nanosheet arrays and the related electrochemical performances[124]: schematic regulation of the interlayer distance(a), electrochemical impedance spectra(b), rate capacities(c)（in Fig.(c), DS is dodecanesulfonate anion. PS is 1-pentanesulfonate anion）

Fig.15 Influences of the interlayer distance on RESR and rate capacity in NiCo-LDH[125]： schematic regulation of interlayer distance(a), RESR(b) and rate capacities(c) of the straight-chain anions intercalated LDHs, RESR (d) and rate capacities(e) of the conjugated-plane anions intercalated LDHs

Table 1 Rate capacities of LDHs-based electrode materials in each strategy (three-electrode test system)

Sample	Capacitance/(F·g^-1)		Ref.	Sample	Capacitance/(F·g^-1)		Ref.
Sample	at low current (≤ 50 A·g^-1)	at high current (> 50 A·g^-1)	Ref.	Sample	at low current (≤ 50 A·g^-1)	at high current (> 50 A·g^-1)	Ref.
regulating compositions				depositing/growing on conductive substrates
NiCoAl-LDH	2062 (1) 553 (20)	―	[28]	CoAl-LDH/CC	616.9 (1) 454.4 (20)	―	[91]
CoNi-LDH	2614 (5)	―	[30]	NiCo-LDH/ N-doped CC	1817 (1)	1092 (100)	[93]
Co^ⅡCo^Ⅲ-LDH	715 (0.5) 130 (50)	―	[32]	CoMn-LDH/CC	1079 (2.1) 891 (42)	―	[94]
amorphizating				NiCo-LDH/CC	1927 (2) 1546 (30)	―	[95]
NiCoMn-LDHs	1440 (1) 1104 (50)	―	[33]	NiCo-LDH/CC	2105 (2) 1191.3 (20)	―	[96]
nanostructuring				NiCo-LDH/NF	2682 (3) 1706 (20)	―	[97]
NiTi-LDH	2310 (1.5) 1206 (30)	―	[36]	MnCo-LDHs@ Ni(OH)₂/NF	2320 (3) 1308 (30)	―	[98]
constructing hierarchical structures				NiMn-LDH/NF	1511 (2.5) 1210 (48)	―	[100]
NiAl-LDH	735 (2) 548 (25)	―	[39]	NiCo-LDH/NF	2184 (1) 1494 (20)	―	[101]
NiCo-LDH	2275.5 (1) 1007.8 (25)	―	[40]	NiCo-LDH/SS	2104 (1)	―	[107]
NiCo-LDH	1887.5 (1) 1187.5 (10)	―	[41]	expanding interlayer distance
NiFe-LDH	1061 (1) 598 (10)	―	[42]	CoFe-LDH	456 (2) 337 (20)	―	[108]
CoAl-LDH	1031 (1) 763 (40)	680 (100)	[43]	CoAl-LDH	1481.7 (1) 856.7 (32)	―	[109]
compositing with carbon				NiCo-LDH	1646 (3) 680 (10)	―	[110]
NiCo-LDH/CNTs	1843 (0.5) 1231 (10)	―	[47]	CoAl-LDH	1100 (1) 750 (30)	―	[112]
NiAl-LDH/CNTs	2034 (1) 1729 (10)	―	[48]	Co^ⅡCo^Ⅲ-LDH	1055 (1) 300 (15)	―	[113]
NiMn-LDH/CNTs	2960 (1.5) 2353 (30)	―	[49]	NiMn-LDH	1881 (1) 649 (10)	―	[114]
NiCo-LDH/CNTs	1896 (1) 1479 (40)	―	[52]	NiCo-LDH	1580 (10)	―	[115]
CoAl-LDH/CNTs	1949.5 (1) 1066.4 (10)	―	[56]	Co^ⅡCo^Ⅲ-LDH	590 (10)	―	[116]
NiCoAl-LDH/rGO	1866 (1) 1360 (10)	―	[57]	selective etching
NiAl-LDH/rGO	2712.7 (1) 1174 (50)	―	[62]	NiCoAl-LDH	1289 (1) 738 (30)	―	[117]
NiCo-LDH/rGO	1911.1 (2) 1469.8 (20)	―	[64]	exfoliation-self-assembly
MgAl-LDH/rGO	1334 (1)	―	[74]	CoAl-LDH/rGO	1043 (1) 912 (20)	―	[120]
CoMn-LDH/rGO	1635 (1) 1161 (10)	―	[75]	CoNi-LDH/ PEDOT:PSS	960 (2) 804 (30)	―	[121]
NiCoAl-LDH/rGO	1544 (1) 1081 (40)	―	[76]	depositing/growing on conductive substrates+ expanding interlayer distance
NiCoAl-LDH/rGO	1544 (1) 1081 (40)	―	[76]	NiAl-LDH/NF	1125 (1)	819 (200)	[124]
NiFe-LDH/rGO	1196 (1) 861 (10)	―	[78]	sub-nanometer-scale fine regulation of interlayer distance
NiCo-LDH/C	2558 (1) 1916 (20)	―	[88]	NiCo-LDH	2115 (1) 949 (50)	626 (100) 410 (150)	[125]

Table 1 Rate capacities of LDHs-based electrode materials in each strategy (three-electrode test system)

Sample	Capacitance/(F·g^-1)		Ref.	Sample	Capacitance/(F·g^-1)		Ref.
Sample	at low current (≤ 50 A·g^-1)	at high current (> 50 A·g^-1)	Ref.	Sample	at low current (≤ 50 A·g^-1)	at high current (> 50 A·g^-1)	Ref.
regulating compositions				depositing/growing on conductive substrates
NiCoAl-LDH	2062 (1) 553 (20)	―	[28]	CoAl-LDH/CC	616.9 (1) 454.4 (20)	―	[91]
CoNi-LDH	2614 (5)	―	[30]	NiCo-LDH/ N-doped CC	1817 (1)	1092 (100)	[93]
Co^ⅡCo^Ⅲ-LDH	715 (0.5) 130 (50)	―	[32]	CoMn-LDH/CC	1079 (2.1) 891 (42)	―	[94]
amorphizating				NiCo-LDH/CC	1927 (2) 1546 (30)	―	[95]
NiCoMn-LDHs	1440 (1) 1104 (50)	―	[33]	NiCo-LDH/CC	2105 (2) 1191.3 (20)	―	[96]
nanostructuring				NiCo-LDH/NF	2682 (3) 1706 (20)	―	[97]
NiTi-LDH	2310 (1.5) 1206 (30)	―	[36]	MnCo-LDHs@ Ni(OH)₂/NF	2320 (3) 1308 (30)	―	[98]
constructing hierarchical structures				NiMn-LDH/NF	1511 (2.5) 1210 (48)	―	[100]
NiAl-LDH	735 (2) 548 (25)	―	[39]	NiCo-LDH/NF	2184 (1) 1494 (20)	―	[101]
NiCo-LDH	2275.5 (1) 1007.8 (25)	―	[40]	NiCo-LDH/SS	2104 (1)	―	[107]
NiCo-LDH	1887.5 (1) 1187.5 (10)	―	[41]	expanding interlayer distance
NiFe-LDH	1061 (1) 598 (10)	―	[42]	CoFe-LDH	456 (2) 337 (20)	―	[108]
CoAl-LDH	1031 (1) 763 (40)	680 (100)	[43]	CoAl-LDH	1481.7 (1) 856.7 (32)	―	[109]
compositing with carbon				NiCo-LDH	1646 (3) 680 (10)	―	[110]
NiCo-LDH/CNTs	1843 (0.5) 1231 (10)	―	[47]	CoAl-LDH	1100 (1) 750 (30)	―	[112]
NiAl-LDH/CNTs	2034 (1) 1729 (10)	―	[48]	Co^ⅡCo^Ⅲ-LDH	1055 (1) 300 (15)	―	[113]
NiMn-LDH/CNTs	2960 (1.5) 2353 (30)	―	[49]	NiMn-LDH	1881 (1) 649 (10)	―	[114]
NiCo-LDH/CNTs	1896 (1) 1479 (40)	―	[52]	NiCo-LDH	1580 (10)	―	[115]
CoAl-LDH/CNTs	1949.5 (1) 1066.4 (10)	―	[56]	Co^ⅡCo^Ⅲ-LDH	590 (10)	―	[116]
NiCoAl-LDH/rGO	1866 (1) 1360 (10)	―	[57]	selective etching
NiAl-LDH/rGO	2712.7 (1) 1174 (50)	―	[62]	NiCoAl-LDH	1289 (1) 738 (30)	―	[117]
NiCo-LDH/rGO	1911.1 (2) 1469.8 (20)	―	[64]	exfoliation-self-assembly
MgAl-LDH/rGO	1334 (1)	―	[74]	CoAl-LDH/rGO	1043 (1) 912 (20)	―	[120]
CoMn-LDH/rGO	1635 (1) 1161 (10)	―	[75]	CoNi-LDH/ PEDOT:PSS	960 (2) 804 (30)	―	[121]
NiCoAl-LDH/rGO	1544 (1) 1081 (40)	―	[76]	depositing/growing on conductive substrates+ expanding interlayer distance
NiCoAl-LDH/rGO	1544 (1) 1081 (40)	―	[76]	NiAl-LDH/NF	1125 (1)	819 (200)	[124]
NiFe-LDH/rGO	1196 (1) 861 (10)	―	[78]	sub-nanometer-scale fine regulation of interlayer distance
NiCo-LDH/C	2558 (1) 1916 (20)	―	[88]	NiCo-LDH	2115 (1) 949 (50)	626 (100) 410 (150)	[125]

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