1. 普鲁士蓝及其衍生物作为氧化物
1.1. 普鲁士蓝作为储能材料的氧化物机理
研究了基于PB和PBA的中空纳米结构氧化物衍生物作为各种可充电电池系统的负极材料[12,
13,
30,
31,
32,
33,34,
35]。例如,PB 立方体可以导出为 Fe
2O
3 [
12]. 这些铁
2O
3微盒具有不同的物理架构。这些铁的物理结构
2O
3微盒是独一无二的。它们的多孔或空心结构可以改善电解质扩散和锂离子在电极中的传输,这种纳米结构可以有效避免充放电过程中的体积变化[
36]。同时,高结晶度和空心铁
+2O
3微盒在长期的充电和放电过程中提供结构稳定性。
除氧化铁外,与结构相关的锂储存特性也可以在PBA衍生的钴氧化物中找到。公司
3O
4由于其易于合成和高比容量,已被用于锂离子电池。由于法拉第过程提供的电荷存储,氧化钴引起了很多关注,并作为储能材料进行了很长时间的研究。各种形式的钴氧化物易于合成,具有非常高的理论电容。公司
3O
4可以在碱性电解质中转化为CoOOH,然后转化为Co
3O
4可以转换为CoO
2 [
37]虽然其理论电容较高,但由于长时间充放电过程中电导率降低和寄生物种的形成,其实际电容较低。此外,膨胀/收缩现象限制了氧化钴基电极的循环寿命。克服这些缺点的主要方法是设计各种高表面积形态。
胡等人成功论证了Co
3O
4源自 Co
3[公司(中国)
6]
2PBA并得到多孔Co
3O
4纳米笼[
15]。易某等发现,多孔Co
3O
4纳米笼作为锂固体笼的负极具有较好的电化学性能.这种纳米结构还具有很高的锂存储容量[
4]。作为一种储能材料,它还显示出许多优点:(1)多孔壳有利于锂扩散;(2)双峰孔径分布和较大的表面积通过缩短Li扩散长度,增加电解液/电极接触面积和增加电解液接触面积来降低电解液电阻;(3)涂层无定形碳能适应循环诱导的应变;(4)表面原子和结构应变由小纳米粒子富集。这些特性使得PBA衍生的多孔Co
++3O
4纳米笼在锂离子电池(LIB)的应用中具有显着优势,可用于制造高性能锂离子电池。所有这些发现都表明,PBA氧化物衍生物作为储能材料具有很大的性能,并且它们将来可用于增强LIB的性能。
1.2. PBA衍生的氧化物作为储能材料的应用
为了追求更高性能的储能材料,研究人员进行了广泛的探索,以进一步改进具有高容量、稳定循环、快速充电能力的新材料。过渡金属氧化物因其易于获得、低成本和高理论比容量,被认为是良好的储能材料[
30]。使用PBA衍生的氧化物纳米材料将改善纳米结构电极材料的优化和设计,提高离子扩散能力和结构稳定性,并使高性能储能材料的生产成为可能。例如,Zhang等人[
12]已经探索了Fe
2O
3由不同温度下的PB立方体制成的盒式二次电池作为LIB的阳极材料。多孔铁
2O
3由Fe组成的微粒
2O
3纳米颗粒可以很容易地通过PB纳米立方体在高温下的氧化和分解来合成。当用作锂离子电池的负极材料时,多孔Fe
2O
3所获得的纳米立方体还显示出优异的循环性能和高比容量(∼800 mA h g
−1在 200 mA g 时
−1).在另一项实验中,研究人员发现Fe
2O
3微盒也受到壳复杂性的影响[
13]。通过PB微立方体的氧化分解和氧化铁壳的晶体生长,证明了具有众多壳结构的各向异性空心结构的可膨胀合成.Fe的循环稳定性
2O
3具有多个壳的微盒明显高于Fe
2O
3具有单壳和双壳的微盒。当用作锂离子电池的负极材料时,Fe
2O
3具有明确的中空结构和带有层状外壳的微孔,显示出高比容量(∼950 mAh g
−1在 200 mA g 时
−1)和出色的循环性能。
同时,金属氧化物与碳材料的结合是提高LIB性能的有益途径。使用两种PB/石墨烯泡沫前驱体,Shao等[
14]成功制备了Fe
2O
3/石墨烯泡沫复合材料。准备好的铁
2O
3/石墨烯泡沫材料用作LIB的独立电极,结合了铅衍生金属氧化物和石墨烯泡沫的优点。它表现出比纯铁更好的储锂性能
2O
3与石墨烯泡沫由于两种组分的协同作用。这些研究结果将有助于开发和改进用于储能的电极材料。
此外,Hu等人[
15]提出了一种新的简单方法来制造多孔Co
3O
4基于Kirkendall效应的纳米笼,其中包括PBA Co的热分解
3[公司(中国)
6]
2在400°C下截断纳米立方体。 这些纳米笼克服了Co的固有缺点。
3O
4阳极具有稳定性、高容量和优异的循环效率。当应用于锂离子电池的电极材料时,制备的Co
3O
4多孔纳米笼表现出优异的电池性能。电流密度为 300 mA g 时
−1,它仍然具有 1465 mA h g 的容量
−150个循环后。金属氧化物具有巨大的存储容量;然而,它们在充电和放电时会受到显着的体积波动并且电导率低。Zhu等人通过煅烧预制PBA Zn克服了这一挑战
3[公司(中国)
6]
2纳米球用于制造自组装的ZnO/Co
3O
4纳米复合材料[
16]。这些氧化锌/钴
3O
4纳米复合材料具有良好的循环和储锂能力。所形成的团簇结构的合理设计,加上双组分功能纳米颗粒体系的协同作用,大大提高了由其产生的电极材料的电化学性能。这种特殊的纳米结构具有优越的储锂能力,为LIBs的进一步优化提供了新的方向。
2. 普鲁士蓝及其衍生物作为硫化物
2.1. 硫化物作为储能材料的机理
近年来,金属硫化物已被证明比等效金属氧化物具有更高的导电性、机械稳定性、热稳定性和电化学活性[
38,
39,
40]。金属硫化物具有比同类金属氧化物更高的导电性,以及丰富的价态、机械和热稳定性,所有这些都有利于电化学性能[
41]。混合金属硫化物作为电化学储能和转换系统的可行电极材料越来越受欢迎[
42]。与单一金属硫化物相比,混合金属硫化物的电化学性能明显更好[
11,
43],这是由于更好的电子导电性和更多样化的氧化还原过程。金属硫化物由于其广泛的氧化还原化学性质、高导电性和两种金属离子的协同作用而成为潜在的电极材料。由于近年来锂硫电池的性能更好,应用广泛,是一种有潜力的新型储能技术,可以满足不断增长的能源需求。典型的LIB由负极、正极、电解质和夹在平行电极之间的隔膜组成[
44,
45,
46]。两种器件的工作原理均为电压驱动阳离子迁移(Na, Li
++,H、K 等)或阴离子(俄勒冈州
++−等)通过电解质朝向电极进行可逆电化学反应。同时,电子通过外部电路流动以保持电荷平衡。这些锂电池需要适当有效的材料,特别是作为基体、夹层和层压金属有机骨架作为新型多孔材料。电极材料的化学特性和物理结构必须适合于高效的储能系统[
47,
48]。金属有机骨架复合材料和MOF衍生物具有更好的性能,减少了纯MOF的缺点[
49,
50]。
先前的研究发现,间质水促进了多价离子的插入和提取。PBA具有优异的电化学性能,因为水削弱了离子之间的静电排斥,降低了离子扩散和界面转移的活化能[
51]。锂离子相对容易嵌入PBA中以进行离子扩散,而钠或钾由于抑制钠/钾扩散和配位水的缺陷而更难包埋。通过控制良好的结晶过程,PBA中的空位和含水量将显着降低,从而提高硫离子电池(SIB)和LIB的循环容量和容量[
52]。PBA及其硫化物衍生物在储能材料的应用中起着重要作用,因为它们为离子和电解质的转移提供了足够的间隙,并为离子的插入提供了许多活性位点。
2.2. 硫化物作为储能材料的应用
PB及其硫化物衍生物因其优异的性能而受到许多研究人员的青睐,因此PB及其硫化物衍生物在储能材料中有许多应用。
以PB为起始原料,经过两步原位转化工艺合成了分级硫化铁纳米立方体,并涂覆多层石墨烯(Fe
1−xS@C/rGO)。当用作SIB的阳极时,梯度纳米立方体表现出323 mAh g的优异倍率能力
−1电流密度为 10 A g 时
−1 [
17.150次循环,铁基钠离子电池的分类为Fe
1−xS@C/rGO阳极,PB阴极容量为323 mAh g
−1.铁
1−xS@C/rGO纳米立方体具有稳定的层状建筑结构和转化过程中获得的高度石墨化的碳,具有良好的钠离子存储性能。石墨烯涂层的纳米立方体结构阻止了硫化铁碳核壳纳米颗粒的融合,也适应了循环过程中的大体积膨胀。碳的高结晶度赋予了良好的电子导电性,使钠离子可及性,并增强了铁的机械耐久性
1−xS@C/rGO纳米立方体。
3. 普鲁士蓝及其衍生物作为硒化物
3.1. 硒化物作为储能材料的机理
最近,许多研究人员对过渡金属硒化物产生了兴趣,它具有高转化率和容量的优点[
54]。与金属硫化物和金属氧化物相比,过渡金属硒化物具有弱金属硒离子键,有利于Li/Na的快速传输[
55,
56]。由于硒(1 × 10)强大的电子导电性,金属硒化物具有循环稳定性和出色的充放电比容量的潜力
++−5S m
−1)和弱电负性。在已发现的钠离子电池正极材料中,具有巨大理论容量的金属硒化物被认为是一个有希望的候选者。然而,金属硒化物负极仍存在电子导电性差、初始库仑效率低、充放电过程中体积变化快等问题。此外,“聚硒化物的穿梭效应”(溶解在正极和负极之间的聚硒化物的穿梭)将导致循环过程中的容量下降。因此,为了缓解这些问题,已经采取了许多缓解措施。MOF因其良好的形貌、高比表面积和均匀的多孔结构,最近被用作制备金属氧化物和硫化物中空结构的前驱体。由于其特殊的尺寸和形状依赖性,PB及其类似物由与刚性有机氰基团配位的金属离子组成,并已发展用于设计和制备各种多孔纳米结构[
33,
57]。
3.2. 硒化物作为储能材料的应用
PBA硒化物衍生物可用于构建具有高比表面积和独特形状的多孔或中空纳米结构,可促进电子传输,同时避免显着的体积膨胀,从而提高电导率[
58,
59,
60]。同时,通过结合不同带隙的纳米材料,可以促进Li/Na的扩散速率,加速表面反应动力学,可以形成具有独特界面效果的双金属硒化物结构设计。PBA硒化物衍生物在储能材料中有着广泛的应用。此外,PBA作为由金属中心和有机连接器组成的MOF,可作为合成多孔材料的自模板[
61]。MOF可以原位限制和生成小尺寸金属颗粒,然后可用于设计金属硒化物。由于它们的优异特性,许多研究人员被吸引来开发和使用它们。
++
4. 普鲁士蓝及其衍生物作为磷化物
4.1. 磷化物作为储能材料的机理
过渡金属磷化物是LIBs极性材料的候选材料之一,因为它们具有良好的极性、高催化活性、热稳定性和化学稳定性[
67,
68,
69]。因此,研究TMP在Li-S电池中的使用至关重要。Huang等人利用密度泛函理论表明,FeP可以与多硫化物形成增强键,促进进一步的氧化还原转化[
70]。Cheng等人[
71]创建了双层Ni-Fe-P/N掺杂碳纳米材料,并证明了其在LIBs中的稳定循环和优异的倍率性能。硬碳和软碳是最常见的负极材料,但它们的容量有限(通常小于300 mAh g
−1) [
72]。 FeP最近被认为是一个潜在的候选者,因为它具有良好的理论容量(926 mAh g
−1)、中等操作潜力和环境友好性[
73]。然而,必须解决与FeP颗粒不可忽略的体积变化和低固有电导率有关的主要问题,这将大大降低动力学与循环稳定性之间的关系[
74]。为了解决前面提到的比容量和循环稳定性之间的权衡,减小粒径可以有效减少扩散长度,同时增加钠扩散系数[
75,
76]。FeP纳米颗粒(12nm)锚定并均匀分散在氮掺杂的碳框架(FeP@NC)上。它具有更大的可逆容量,为253.9 mAh g
−1低于 2 A g
−1 [
77]. 考虑到Fe在PB框架中的均匀分布,预计PB的磷化/碳化将导致FeP纳米颗粒在碳基体中的均匀分布。
4.2. 磷化物作为储能材料的应用
PBA磷化物衍生物在储能材料中的优异性能使其受到许多研究人员的青睐,许多研究人员已经开发和应用了它们。
Song等人[
20]使用Fe-Ni-P@nitrogen掺杂的碳(Fe-Ni-P@NC),衍生自Fe-Ni PBA,用作Li-S电池的高效硫宿主。Fe-Ni-P颗粒不仅有效促进LiPS的转化,而且提高了LiPS的吸附性。此外,PBAs的CN-在热解过程中容易转化为氮掺杂碳,可以提高复合材料的导电性。由于这些优点,具有S@Fe-Ni-P@NC复合阴极的LIBs/SIBs表现出优异的电化学性能、优异的倍率能力,在500 °C下循环1次,每次循环的容量衰减率低,为0.08%。
By combining the tubular PB cathode with its derived phosphating anode, Jiang et al. demonstrated an excellent sodium ion battery [
22]. Because of the tubular configuration, the PB has fast reaction kinetics and, thus, a high specific capacity of 94.4 mAh g
−1 even at a high rate of 5.0 A g
−1. PB-derived phosphides are characterized by encapsulating FeP nanoparticles in a conductive carbon matrix, thereby achieving excellent sodium energy storage. The as-assembled sodium-ion full cell has a record capacity of 105.3 mAh g
−1 at 2.0 A g
−1 and a long cycling lifetime. Their research proposes a homologous design strategy for outstanding sodium-ion full cells based on PB and its derivatives.
5. Prussian Blue and Its Derivatives as Boride
5.1. Mechanism of Boride as Energy Storage Material
Metal borides’ electrochemical properties have been extensively researched due to their high chemical stability, low cost, conductivity, and unique electronic interaction between boron atoms and metal atoms [
78]. Metal boride nanostructures can open up an entirely new dimension for harnessing these properties. Nanostructures can provide advantages such as increased surface area, easier access to exposed catalytic centers, faster reaction rate kinetics, tunable electronic structures, and lower charge transfer resistance [
79,
80]. Recent research has revealed that transition metal borides have the potential to be effective electrocatalysts for water splitting [
81,
82,
83]. Bimetallic and ternary borides have been shown to have higher electrocatalytic activity than single-metal borides due to a synergistic effect [
84,
85]. Schuhmann et al. used operando X-ray absorption spectroscopy on ultrathin nickel boride nanosheets to demonstrate this aspect [
82]. These studies clearly illustrate that the surface oxidation states change from Ni
2+ to Ni
3+ during the oxygen evolution reaction (OER) process, resulting in the formation of a NiO(OH) surface layer on a NiB@NiO(OH) core–shell structure. Amorphous cobalt boride nanosheets are also effective at OER electrocatalytic water splitting [
86]. NiCoB and NiFeB nanosheet heterostructures with r-GO and single phase borated metal boride layers exhibit good performance in OER electrocatalysis [
87,
88]. The presence of heteroatoms is thought to reduce charge transfer resistance, increase the density of active catalytic sites, and ease electronic state regulation. As a type of MOF family, PBAs have been used as precursors or templates for metal hydroxides, phosphides, and sulfides. PBAs can be converted into various nanostructured metal borides by mild chemical reduction based on their different structures and metal ions. Many researchers worked on developing this material, which has excellent performance in the field of energy storage.
5.2. Application of Boride as Energy Storage Material
PBA boride derivatives have been developed and utilized for their excellent properties in energy storage materials. He et al. synthesize amorphous Co-Ni-B-O nanosheets (CNBO-NSs) by chemically reducing bimetallic PBA (Co-Ni PBAs) with sodium borohydride [
23]. The electrochemical catalytic activity and stability of the as-prepared CNBO-NSs are excellent. During 24 h operation, they can maintain a current density of 10 mA cm
−2 at 140 mV over potential for hydrogen evolution and 300 mV for oxygen evolution. The formation of metal boron bonds, as well as an increase in surface area and conductivity in the CNBO-NS structure, are the factors that contribute to the increase in catalytic activity. This research can provide new insights for the application of MOF in the design of functional nanomaterials, as well as valuable insights for efficient electrolytic energy conversion and other aspects of crystallization engineering. As an efficient and durable electrocatalyst for OER, CoFe-based nanomaterials derived from PBA have increased specific surface area and rich catalytic active sites. Yang et al. [
24] found that due to the adjustable chemical conformation and controllable 3D morphology, CoFe-B nano cube has a nano cube structure wrapped in ultra-thin nano sheets, and has excellent electrocatalytic performance and remarkable reaction kinetics in 1.0 m KOH aqueous solution. Furthermore, CoFe-B nano cubes have overpotentials of 261 and 338 mV at current densities of 10 and 200 mA cm
−2, respectively, with a small Tafel slope of 61 mV dec1 for OER. The unique ultra-thin nano sheet wrapped nano cube structure is largely responsible for the excellent electrocatalysis performance. This work not only introduces a new method for using PBA, but it also introduces an efficient scheme for electrocatalysis.
6. Prussian Blue and Its Derivatives as Carbide
6.1. Mechanism of Carbide as Energy Storage Material
Metal carbides are ideal electrode materials for electrochemical storage devices (such as LIB and the supercapacitor) because of their excellent stability, good conductivity, and high theoretical capacity [
89,
90]. Metal carbides have greater electronic conductivity and mechanical stability, as well as corrosion resistance, due to their special atomic structure in which carbon atoms are found in the voids between densely packed metallic host atoms [
90,
91]. Gogotis et al. proved that two-dimensional layered carbides can be used as anode materials for LIBs, and found that the Li storage mechanism is the intercalation and de intercalation of Li layers. Furthermore, Gogotsi and his colleagues demonstrated the potential of layered carbides as electrode materials for supercapacitors [
92]. When PBAs are combined with carbides, two-dimensional layered carbides act as a binder and conductive additive to connect the nanoparticles, facilitating charge transfer and avoiding the significant drop in electrode conductivity that would otherwise occur. PBAs can increase interlayer space, electrolyte diffusion, and battery electrochemical activity, making them perfect for all aspects of the energy storage sector. In addition, metal carbides and carbon-encapsulated metal/metal alloys exhibit outstanding electrocatalytic activity due to the synergistic impact between carbon materials and metals. PB/PBA nanoparticles with uniform element distribution and abundant cyanide ligands are also being investigated as chemical precursors for the preparation of catalytic metal carbides and carbon-encapsulated metal/metal alloys [
93]. Because of the superior features of metal carbides, they offer significant benefits in the fields of energy storage and electrocatalysis, and they are frequently investigated and implemented in practice.
++
6.2. Application of Carbide as Energy Storage Material
It is an effective method to use PBA as the precursor and provide two metal elements at the same time to form bimetallic carbide and carbon skeleton nanocomposites with distinct structures. Ma et al. developed a method of implanting uniformly distributed carbide nanoparticles into a spherical porous carbon framework to form microspheres similar to pitaya [
25]. The synthesized pitaya-shaped microspheres can effectively buffer volume changes and prevent Co
3ZnC nanoparticles from aggregating during the charging/discharging process of LIBs due to their unique composition and structural characteristics. The porous carbon framework allows unimpeded electron transmission and Li diffusion, and restricts the thin solid electrolyte interface layer to the outer surface of the carbon shell. After 300 charge/discharge cycles, the anodes in LIBs deliver a high capacity of 608 mA h g
−1 at 100 mA g
−1 and ultrahigh cyclic stability and rate performance with a capacity of 423 mA h g
−1 even after 1150 consecutive cycles at 1000 mA g
−1.
The thermal decomposition of PB produced Fe/Fe
3C without altering its original morphology, but the surface area and porosity increased significantly [
94]. Due to the presence of metallic iron, each of these Fe/Fe
3C nanoparticles is uniformly coated with several layers of graphite carbon, which enhances its stability and electronic conductivity. Kumar et al. reported for the first time a one-step method for manufacturing the unique superstructure of carbon-encapsulated Fe/Fe
3C nanocomposites for supercapacitor electrodes [
26]. Nanocomposites with carbon encapsulation have excellent cycle stability and no capacitance decay after 20000 CV cycles. Asymmetric supercapacitors exhibit good electrochemical performance in terms of capacitance, energy, power density, and cycle stability when assembled, which is practical for future applications.