Heterojunction Ferroelectric Materials Enhance Ion Transport and Fast Charging of Polymer Solid Electrolytes for Lithium Metal Batteries
异质结铁电材料增强锂金属电池聚合物固体电解质的离子传输和快速充电

In recent years, the evolution of battery-powered consumer electronics, and grid energy storage has driven the demand for
近年来，电池供电的消费电子产品和电网储能的发展推动了对

high-energy-density batteries. ${}^{[1]}$${}^{[1]}$^([1]){ }^{[1]} Traditional organic liquid electrolytes (LE) pose a high safety risk due to their flammability. In contrast, solid polymer electrolytes (SPEs) have drawn significant attention owing to their excellent safety, simplicity in preparation, good mechanical properties, and remarkable chemical stability. Those characteristics, when combined with the extremely outstanding theoretical energy density ( $3860\mathrm{mAh}\mathrm{g}{}^{-1}$$3860\mathrm{mAh}\mathrm{g}{}^{-1}$3860mAhg^(-1)3860 \mathrm{mAh} \mathrm{g}{ }^{-1} ) of the Li metal anode, render it a highly potential contender for the succeeding period of batteries. ${}^{[2]}$${}^{[2]}$^([2]){ }^{[2]}
高能量密度电池。 ${}^{[1]}$${}^{[1]}$^([1]){ }^{[1]} 传统的有机液体电解质 （LE） 由于其易燃性而存在很高的安全风险。相比之下，固体聚合物电解质 （SPE） 因其出色的安全性、制备简单、良好的机械性能和卓越的化学稳定性而受到广泛关注。这些特性与锂金属负极极其出色的理论能量密度 （ $3860\mathrm{mAh}\mathrm{g}{}^{-1}$$3860\mathrm{mAh}\mathrm{g}{}^{-1}$3860mAhg^(-1)3860 \mathrm{mAh} \mathrm{g}{ }^{-1} ） 相结合，使其成为后续电池极具潜力的竞争者。 ${}^{[2]}$${}^{[2]}$^([2]){ }^{[2]}

Poly(ethylene oxide) (PEO), a widely studied polymeric solid electrolyte, has a limited ionic conductivity efficiency at room temperature because of its significant crystallinity. ${}^{[3]}$${}^{[3]}$^([3]){ }^{[3]} In contrast, its mechanical properties deteriorate at high temperatures, which is unfavorable for practical applications. Compared to PEO, PVDF is a partially -crystalline polar polymer having a high dielectric constant $\left({ϵ}_{\mathrm{r}}\right)$$\left({ϵ}_{\mathrm{r}}\right)$(epsilon_(r))\left(\epsilon_{\mathrm{r}}\right), which can enhance the interaction of the substrate with the lithium salts and accelerate the dissolution of lithium salts and ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+}transport. ${}^{[4]}$${}^{[4]}$^([4]){ }^{[4]} In addition, PVDF has high thermal stability, which allows it to have good mechanical properties at high temperatures, and a higher electrochemical window than PEO, which makes PVDF a material drawing substantial attention in the realm of solid-state polymer electrolytes in recent years. Nevertheless, there remains considerable potential for enhancement with regard to the overall performance of PVDF-SPE. Forinstance, the homopolymer structure of PVDF results in high intramolecular crystallinity (typically above 65%), which is not conducive to ion transport. In addition, solid-state electrolytes with PVDF as the base can rely on the adsorption of trace amounts of solvents (e.g., $\mathrm{N},\mathrm{N}$$\mathrm{N},\mathrm{N}$N,N\mathrm{N}, \mathrm{N}-dimethylformamide (DMF)) for lithium-ion transport, but solvent residues might have an effect on the stability of the electrolyte in electrochemical terms and bring about interfacial side reactions. ${}^{[5]}$${}^{[5]}$^([5]){ }^{[5]} In summary, the main problem with PVDF-SPE is its low ionic conductivity, which limits its use in high energy-density electric fields, particularly in applications requiring rapid charge and discharge.
聚环氧乙烷 （PEO） 是一种被广泛研究的聚合物固体电解质，由于其显着的结晶度，在室温下的离子电导效率有限。 ${}^{[3]}$${}^{[3]}$^([3]){ }^{[3]} 相反，其机械性能在高温下会变差，不利于实际应用。与 PEO 相比，PVDF 是一种具有高介电常 $\left({ϵ}_{\mathrm{r}}\right)$$\left({ϵ}_{\mathrm{r}}\right)$(epsilon_(r))\left(\epsilon_{\mathrm{r}}\right) 数的部分结晶极性聚合物，可以增强衬底与锂盐的相互作用，加速锂盐的溶解和 ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+} 传输。 ${}^{[4]}$${}^{[4]}$^([4]){ }^{[4]} 此外，PVDF 具有很高的热稳定性，使其在高温下具有良好的机械性能，并且具有比 PEO 更高的电化学窗口，这使得 PVDF 成为近年来在固态聚合物电解质领域引起广泛关注的材料。尽管如此，PVDF-SPE 的整体性能仍有相当大的提升潜力。例如，PVDF 的均聚物结构导致高分子内结晶度（通常高于 65%），这不利于离子传输。此外，以 PVDF 为基的固态电解质可以依靠微量溶剂（例如- $\mathrm{N},\mathrm{N}$$\mathrm{N},\mathrm{N}$N,N\mathrm{N}, \mathrm{N} 二甲基甲酰胺 （DMF））的吸附进行锂离子传输，但溶剂残留可能会对电解质的电化学稳定性产生影响，并带来界面副反应。 ${}^{[5]}$${}^{[5]}$^([5]){ }^{[5]} 总之，PVDF-SPE 的主要问题是其低离子电导率，这限制了它在高能量密度电场中的使用，特别是在需要快速充电和放电的应用中。
Researchers have devised a range of strategic solutions for the enhancement of the ionic conductivity of PVDF-SPE. Among
研究人员为增强 PVDF-SPE 的离子电导率设计了一系列战略解决方案。中
these strategies, the introduction of fillers is regarded as the most promising approach to optimizing the conductivity of electricity and the mechanical strength of PVDF-SPE ${}^{[6]}$${}^{[6]}$^([6]){ }^{[6]} For example, $\mathrm{h}-\mathrm{BN},{}^{[7]}{\mathrm{Al}}_2{\mathrm{O}}_3,{}^{[8]}{\mathrm{Li}}_{0.33}{\mathrm{La}}_{0.557}{\mathrm{TiO}}_3,{}^{[9]}{\mathrm{Li}}_{1.4}{\mathrm{Al}}_{0.4}{\mathrm{Ti}}_{1.6}\left({\mathrm{PO}}_4\right),{}^{[10]}$$\mathrm{h}-\mathrm{BN},{}^{[7]}{\mathrm{Al}}_2{\mathrm{O}}_3,{}^{[8]}{\mathrm{Li}}_{0.33}{\mathrm{La}}_{0.557}{\mathrm{TiO}}_3,{}^{[9]}{\mathrm{Li}}_{1.4}{\mathrm{Al}}_{0.4}{\mathrm{Ti}}_{1.6}\left({\mathrm{PO}}_4\right),{}^{[10]}$h-BN,^([7])Al_(2)O_(3),^([8])Li_(0.33)La_(0.557)TiO_(3),^([9])Li_(1.4)Al_(0.4)Ti_(1.6)(PO_(4)),^([10])\mathrm{h}-\mathrm{BN},{ }^{[7]} \mathrm{Al}_{2} \mathrm{O}_{3},{ }^{[8]} \mathrm{Li}_{0.33} \mathrm{La}_{0.557} \mathrm{TiO}_{3},{ }^{[9]} \mathrm{Li}_{1.4} \mathrm{Al}_{0.4} \mathrm{Ti}_{1.6}\left(\mathrm{PO}_{4}\right),{ }^{[10]} and ${\mathrm{Li}}_{6.75}{\mathrm{La}}_3{\mathrm{Zr}}_{1.7}{\mathrm{TiO}}^{[11]}$${\mathrm{Li}}_{6.75}{\mathrm{La}}_3{\mathrm{Zr}}_{1.7}{\mathrm{TiO}}^{[11]}$Li_(6.75)La_(3)Zr_(1.7)TiO^([11])\mathrm{Li}_{6.75} \mathrm{La}_{3} \mathrm{Zr}_{1.7} \mathrm{TiO}^{[11]} In addition, several metal-organic frameworks (MOFs) ${}^{[12]}$${}^{[12]}$^([12]){ }^{[12]} and covalent organic frameworks (COFs) ${}^{[13]}$${}^{[13]}$^([13]){ }^{[13]} have been embedded in the PVDF matrix to improve the comprehensive performance of PVDF-SPE. Among all these materials, ferroelectric substances exhibit great potential for facilitating ion transport and thereby enhancing reaction kinetics due to their unique non-centrosymmetric crystal structure and spontaneous polarization. Consequently, a variety of ferroelectric materials, including ${\mathrm{BaTiO}}_3,{}^{[14]}{\mathrm{LiTaO}}_3,{}^{[15]}{\mathrm{Bi}}_4{\mathrm{Ti}}_3{\mathrm{O}}_{12},{}^{[16]}\mathrm{P}(\mathrm{VDF}-\mathrm{TrFE}),{}^{[17]}$${\mathrm{BaTiO}}_3,{}^{[14]}{\mathrm{LiTaO}}_3,{}^{[15]}{\mathrm{Bi}}_4{\mathrm{Ti}}_3{\mathrm{O}}_{12},{}^{[16]}\mathrm{P}(\mathrm{VDF}-\mathrm{TrFE}),{}^{[17]}$BaTiO_(3),^([14])LiTaO_(3),^([15])Bi_(4)Ti_(3)O_(12),^([16])P(VDF-TrFE),^([17])\mathrm{BaTiO}_{3},{ }^{[14]} \mathrm{LiTaO}_{3},{ }^{[15]} \mathrm{Bi}_{4} \mathrm{Ti}_{3} \mathrm{O}_{12},{ }^{[16]} \mathrm{P}(\mathrm{VDF}-\mathrm{TrFE}),{ }^{[17]} and $P(VDF-TrFE-CTFE),{}^{[18]}$$P(VDF-TrFE-CTFE),{}^{[18]}$P(VDF-TrFE-CTFE),^([18])P(V D F-T r F E-C T F E),{ }^{[18]} have been effectively utilized for enhancing the interfacial ion transport kinetics of SPE. As Wang et al. have demonstrated, ferroelectric materials can effectively repress the space charge layer (SCL) ${}^{[19]}$${}^{[19]}$^([19]){ }^{[19]} and promote ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+}transport at the interface between the solid-state electrolyte and the lithium metal anode. ${}^{[20]}$${}^{[20]}$^([20]){ }^{[20]} Once the electric field at the interface region locally is homogenized, the “tip effect” of the lithium anode can be effectively mitigated. Examples of this phenomenon include the enhancement of ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+}transport by incorporating ceramic fillers into the electrolyte, as well as phase modulation and co-polymerization strategies to enhance the dielectric constant of PVDF. In particular, Kang et al. reported the synthesis of heterostructured BTO-LLTO nanowires. The ferroelectric ceramic ${\mathrm{BaTiO}}_3$${\mathrm{BaTiO}}_3$BaTiO_(3)\mathrm{BaTiO}_{3} (BTO) significantly facilitated the disassociation of lithium salts, resulting in an increase of the mobility of ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+}. Additionally, the BTO-LLTO productively inhibits the generation of a space charge layer at the electrolyte-anode interface. ${}^{[21]}$${}^{[21]}$^([21]){ }^{[21]} Furthermore, there have been studies showing that the incorporation of ferroelectric materials with lithium-ion conductive property can enhance the ionic conduction of solid electrolytes. As an example, Kang et al. promoted the transport of ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+}by incorporating ${\mathrm{LiTaO}}_3$${\mathrm{LiTaO}}_3$LiTaO_(3)\mathrm{LiTaO}_{3}, a ferroelectric ceramic ionic conductor possessing an ionic conductivity of $2.19\times {10}^{-6}\mathrm{S}{\mathrm{cm}}^{-1}$$2.19\times {10}^{-6}\mathrm{S}{\mathrm{cm}}^{-1}$2.19 xx10^(-6)Scm^(-1)2.19 \times 10^{-6} \mathrm{~S} \mathrm{~cm}^{-1}, into a solid polymer electrolyte. The automatic polarization of the ferroelectric ceramic ${\mathrm{LiTaO}}_3$${\mathrm{LiTaO}}_3$LiTaO_(3)\mathrm{LiTaO}_{3} under an applied electric field resulted in the weakening of the SCL between the polymer and ceramic filler. Modifying the dielectric constant $\left({\epsilon }_{\mathrm{r}}\right)$$\left({\epsilon }_{\mathrm{r}}\right)$(epsi_(r))\left(\varepsilon_{\mathrm{r}}\right) and the phase structure of the ferroelectric polymer matrix represents a productive method to enhance the ionic conductivity of solid polymer electrolytes. For example, He et al. employed P(VDF-TrFE-CTFE) as a novel polymer substrate, and the P(VDF-TrFE-CTFE)-based SPEs exhibited enhanced TTTT conformation. ${}^{[18]}$${}^{[18]}$^([18]){ }^{[18]} The enhanced polarity associated with the TTTT conformation further augmented the ferroelectricity and the high dielectric constant (er), which facilitated lithium dissociation and elevated lithium-ion mobility. Although these measures improved ionic conductivity and enhanced the performance of PVDF-SPE, critical issues such as safety, residual solvents, and interfacial side reactions were overlooked. Furthermore, research on ferroelectric materials in polymer solidstate electrolytes remains relatively underexplored. Most studies have focused on single-material systems, with limited attention given to the potential role of multifunctional heterojunction ferroelectric fillers in PVDF-SPE through strategically designed composites.
这些策略，填料的引入被认为是优化电导率和 PVDF-SPE ${}^{[6]}$${}^{[6]}$^([6]){ }^{[6]} 机械强度的最有前途的方法， $\mathrm{h}-\mathrm{BN},{}^{[7]}{\mathrm{Al}}_2{\mathrm{O}}_3,{}^{[8]}{\mathrm{Li}}_{0.33}{\mathrm{La}}_{0.557}{\mathrm{TiO}}_3,{}^{[9]}{\mathrm{Li}}_{1.4}{\mathrm{Al}}_{0.4}{\mathrm{Ti}}_{1.6}\left({\mathrm{PO}}_4\right),{}^{[10]}$$\mathrm{h}-\mathrm{BN},{}^{[7]}{\mathrm{Al}}_2{\mathrm{O}}_3,{}^{[8]}{\mathrm{Li}}_{0.33}{\mathrm{La}}_{0.557}{\mathrm{TiO}}_3,{}^{[9]}{\mathrm{Li}}_{1.4}{\mathrm{Al}}_{0.4}{\mathrm{Ti}}_{1.6}\left({\mathrm{PO}}_4\right),{}^{[10]}$h-BN,^([7])Al_(2)O_(3),^([8])Li_(0.33)La_(0.557)TiO_(3),^([9])Li_(1.4)Al_(0.4)Ti_(1.6)(PO_(4)),^([10])\mathrm{h}-\mathrm{BN},{ }^{[7]} \mathrm{Al}_{2} \mathrm{O}_{3},{ }^{[8]} \mathrm{Li}_{0.33} \mathrm{La}_{0.557} \mathrm{TiO}_{3},{ }^{[9]} \mathrm{Li}_{1.4} \mathrm{Al}_{0.4} \mathrm{Ti}_{1.6}\left(\mathrm{PO}_{4}\right),{ }^{[10]} ${\mathrm{Li}}_{6.75}{\mathrm{La}}_3{\mathrm{Zr}}_{1.7}{\mathrm{TiO}}^{[11]}$${\mathrm{Li}}_{6.75}{\mathrm{La}}_3{\mathrm{Zr}}_{1.7}{\mathrm{TiO}}^{[11]}$Li_(6.75)La_(3)Zr_(1.7)TiO^([11])\mathrm{Li}_{6.75} \mathrm{La}_{3} \mathrm{Zr}_{1.7} \mathrm{TiO}^{[11]} 此外，PVDF 基质中嵌入了几种金属有机框架 （MOF） ${}^{[12]}$${}^{[12]}$^([12]){ }^{[12]} 和共价有机框架 （COF）， ${}^{[13]}$${}^{[13]}$^([13]){ }^{[13]} 以提高 PVDF-SPE 的综合性能。在所有这些材料中，铁电物质由于其独特的非中心对称晶体结构和自发极化，在促进离子传输方面表现出巨大的潜力，从而增强反应动力学。因此，各种铁电材料，包括 ${\mathrm{BaTiO}}_3,{}^{[14]}{\mathrm{LiTaO}}_3,{}^{[15]}{\mathrm{Bi}}_4{\mathrm{Ti}}_3{\mathrm{O}}_{12},{}^{[16]}\mathrm{P}(\mathrm{VDF}-\mathrm{TrFE}),{}^{[17]}$${\mathrm{BaTiO}}_3,{}^{[14]}{\mathrm{LiTaO}}_3,{}^{[15]}{\mathrm{Bi}}_4{\mathrm{Ti}}_3{\mathrm{O}}_{12},{}^{[16]}\mathrm{P}(\mathrm{VDF}-\mathrm{TrFE}),{}^{[17]}$BaTiO_(3),^([14])LiTaO_(3),^([15])Bi_(4)Ti_(3)O_(12),^([16])P(VDF-TrFE),^([17])\mathrm{BaTiO}_{3},{ }^{[14]} \mathrm{LiTaO}_{3},{ }^{[15]} \mathrm{Bi}_{4} \mathrm{Ti}_{3} \mathrm{O}_{12},{ }^{[16]} \mathrm{P}(\mathrm{VDF}-\mathrm{TrFE}),{ }^{[17]} 并 $P(VDF-TrFE-CTFE),{}^{[18]}$$P(VDF-TrFE-CTFE),{}^{[18]}$P(VDF-TrFE-CTFE),^([18])P(V D F-T r F E-C T F E),{ }^{[18]} 已被有效地用于增强 SPE 的界面离子传输动力学。正如 Wang 等人所证明的那样，铁电材料可以有效地抑制空间电荷层 （SCL） ${}^{[19]}$${}^{[19]}$^([19]){ }^{[19]} 并促进 ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+} 固态电解质和锂金属阳极之间界面的传输。 ${}^{[20]}$${}^{[20]}$^([20]){ }^{[20]} 一旦界面区域的电场局部均匀化，就可以有效减轻锂阳极的“尖端效应”。这种现象的示例包括通过将陶瓷填料掺入电解质来增强 ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+} 传输，以及提高 PVDF 介电常数的相位调制和共聚策略。特别是，Kang 等人报道了异质结构 BTO-LLTO 纳米线的合成。铁电陶瓷 ${\mathrm{BaTiO}}_3$${\mathrm{BaTiO}}_3$BaTiO_(3)\mathrm{BaTiO}_{3} （BTO） 显著促进了锂盐的解离，导致 ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+} 的迁移率增加。 此外，BTO-LLTO 有效地抑制了电解质-阳极界面处空间电荷层的产生。 ${}^{[21]}$${}^{[21]}$^([21]){ }^{[21]} 此外，有研究表明，具有锂离子导电特性的铁电材料的掺入可以增强固体电解质的离子传导。例如，Kang 等人通过将具有 离子电导率的 $2.19\times {10}^{-6}\mathrm{S}{\mathrm{cm}}^{-1}$$2.19\times {10}^{-6}\mathrm{S}{\mathrm{cm}}^{-1}$2.19 xx10^(-6)Scm^(-1)2.19 \times 10^{-6} \mathrm{~S} \mathrm{~cm}^{-1} 铁电陶瓷离子导体掺入 ${\mathrm{LiTaO}}_3$${\mathrm{LiTaO}}_3$LiTaO_(3)\mathrm{LiTaO}_{3} 固体聚合物电解质中来促进其 ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+} 传输。铁电陶瓷 ${\mathrm{LiTaO}}_3$${\mathrm{LiTaO}}_3$LiTaO_(3)\mathrm{LiTaO}_{3} 在外加电场下的自动极化导致聚合物和陶瓷填料之间的 SCL 减弱。改变铁电聚合物基体的介电常数 $\left({\epsilon }_{\mathrm{r}}\right)$$\left({\epsilon }_{\mathrm{r}}\right)$(epsi_(r))\left(\varepsilon_{\mathrm{r}}\right) 和相结构是增强固体聚合物电解质离子电导率的有效方法。例如，He 等人采用 P（VDF-TrFE-CTFE） 作为新型聚合物底物，基于 P（VDF-TrFE-CTFE） 的 SPE 表现出增强的 TTTT 构象。 ${}^{[18]}$${}^{[18]}$^([18]){ }^{[18]} 与 TTTT 构象相关的增强极性进一步增强了铁电性和高介电常数 （er），从而促进了锂解离和锂离子迁移率的提高。尽管这些措施提高了离子电导率并增强了 PVDF-SPE 的性能，但安全性、残留溶剂和界面副反应等关键问题被忽视了。此外，对聚合物固态电解质中铁电材料的研究仍然相对不足。 大多数研究都集中在单一材料体系上，而对多功能异质结铁电填料通过战略设计的复合材料在 PVDF-SPE 中的潜在作用的关注有限。
${\mathrm{BaTiO}}_3$${\mathrm{BaTiO}}_3$BaTiO_(3)\mathrm{BaTiO}_{3} with a high dielectric constant $(\approx {10}^3)$$\left(\approx {10}^3\right)$(~~10^(3))\left(\approx 10^{3}\right) is the most extensively researched ferroelectric ceramic material. The tetrag-
${\mathrm{BaTiO}}_3$${\mathrm{BaTiO}}_3$BaTiO_(3)\mathrm{BaTiO}_{3} 具有高介电常数 $(\approx {10}^3)$$\left(\approx {10}^3\right)$(~~10^(3))\left(\approx 10^{3}\right) 的是研究最广泛的铁电陶瓷材料。四面体-
onal phase is polarized by the movement of ${\mathrm{Ti}}^{4+}$${\mathrm{Ti}}^{4+}$Ti^(4+)\mathrm{Ti}^{4+} and ${\mathrm{O}}^{2-}$${\mathrm{O}}^{2-}$O^(2-)\mathrm{O}^{2-} electrons in the octahedral configuration in te presence of an exerted electric field, resulting in excellent piezoelectric/ferroelectric properties. ${}^{[22]}$${}^{[22]}$^([22]){ }^{[22]} The preparation of 1D nanowire structures with high aspect ratios from ${\mathrm{BaTiO}}_3$${\mathrm{BaTiO}}_3$BaTiO_(3)\mathrm{BaTiO}_{3} nanoparticles is aimed to construct constructing continuous and long-range lithium-ion transport paths. ${}^{[23]}$${}^{[23]}$^([23]){ }^{[23]} The nanowire fillers possess a more extensive contact region with the polymer substrate, which facilitates the establishment of productive ion conduction pathway. ${}^{[24]}$${}^{[24]}$^([24]){ }^{[24]} Additionally, 2D transition metal-sulfur compound materials are also being widely utilized as filler components in polymer solid-state electrolytes. ${\mathrm{MoSe}}_2$${\mathrm{MoSe}}_2$MoSe_(2)\mathrm{MoSe}_{2} (MS) has demonstrated considerable potential for application in lithium-ion and magnesium-ion batteries because of its distinctive laminar structure which facilitates enhanced ion mobility. Moreover, the presence of weak van der Waals forces also contributes to its good performance. ${}^{[25]}$${}^{[25]}$^([25]){ }^{[25]} The application of external forces results in 2D nanosheets being more prone to slip within the polymer matrix than 1D nanowires, which helps to protect the electrolyte from deformation and rupture while restraining the expansion of lithium dendrites. It is therefore proposed that the ion transport network be constructed using the nanowires as a backbone and the nanosheets as an extension. The resulting configuration would provide a more complete 3D network. Furthermore, the electric field produced by the distribution of charge at the heterojunction interface is anticipated to facilitate the decomposition of lithium compound and accelerate ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+}transport. ${}^{[26]}$${}^{[26]}$^([26]){ }^{[26]}
在 TE 存在电场的情况下，八面体构型中的电子运动使 ${\mathrm{Ti}}^{4+}$${\mathrm{Ti}}^{4+}$Ti^(4+)\mathrm{Ti}^{4+} ONAL ${\mathrm{O}}^{2-}$${\mathrm{O}}^{2-}$O^(2-)\mathrm{O}^{2-} 相极化，从而获得优异的压电/铁电性能。 ${}^{[22]}$${}^{[22]}$^([22]){ }^{[22]} 从纳米颗粒制备 ${\mathrm{BaTiO}}_3$${\mathrm{BaTiO}}_3$BaTiO_(3)\mathrm{BaTiO}_{3} 具有高纵横比的 1D 纳米线结构旨在构建连续和长距离锂离子传输路径。 ${}^{[23]}$${}^{[23]}$^([23]){ }^{[23]} 纳米线填料与聚合物衬底具有更广泛的接触区域，这有助于建立有效的离子传导途径。 ${}^{[24]}$${}^{[24]}$^([24]){ }^{[24]} 此外，二维过渡金属-硫化合物材料也被广泛用作聚合物固态电解质中的填充成分。 ${\mathrm{MoSe}}_2$${\mathrm{MoSe}}_2$MoSe_(2)\mathrm{MoSe}_{2} （MS） 因其独特的层状结构而有助于增强离子迁移率，因此在锂离子电池和镁离子电池中显示出相当大的应用潜力。此外，弱范德华力的存在也有助于其良好的性能。 ${}^{[25]}$${}^{[25]}$^([25]){ }^{[25]} 外力的应用导致 2D 纳米片比 1D 纳米线更容易在聚合物基体内滑动，这有助于保护电解质免受变形和破裂，同时抑制锂枝晶的膨胀。因此，建议以纳米线为主链，纳米片为延伸来构建离子传输网络。生成的配置将提供更完整的 3D 网络。此外，异质结界面上的电荷分布产生的电场有望促进锂化合物的分解并加速 ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+} 传输。 ${}^{[26]}$${}^{[26]}$^([26]){ }^{[26]}

In this study, we have prepared a novel 1D structured ferroelectric ceramic-based heterojunction nanofiber and compounded it into a solid polymer electrolyte. This action has been taken to construct an interfacial electric field, which in turn promotes the dissociation and rapid as well as uniform deposition of lithium salts. Furthermore, a long-range organic/inorganic interface was constructed to serve as a lithium-ion transport pathway using electrostatic spinning technology. The ${\mathrm{MoSe}}_2$${\mathrm{MoSe}}_2$MoSe_(2)\mathrm{MoSe}_{2} hydrothermally grown on the surface further increased the specific surface area and provided the interfacial electric field, a new pathway for ion dissociation and transport, which further enhanced the performance of PVDF-SPE. The BTO-MS heterojunction nanofibers (BTO-MS HNFs) may also reduce the interfacial electrical potential aimed the electrolyte and the lithium metal cathode as well as weaken the SCL. These synergistic effects create superior performance. The LFP/PVBM/Li cell displayed a capacity of $110.7\mathrm{mAh}{\mathrm{g}}^{-1}$$110.7\mathrm{mAh}{\mathrm{g}}^{-1}$110.7mAhg^(-1)110.7 \mathrm{mAh} \mathrm{g}^{-1} at 5 C , with a capacity retainment rate of $82.6\mathrm{\%}$$82.6\mathrm{\%}$82.6%82.6 \% after 1500 cycles. The LFP/Li soft pack battery, assembled with PVBM, demonstrated a capacity of $127.8\mathrm{mAh}{\mathrm{g}}^{-1}$$127.8\mathrm{mAh}{\mathrm{g}}^{-1}$127.8mAhg^(-1)127.8 \mathrm{mAh} \mathrm{g}^{-1} and preserved $\approx 97\mathrm{\%}$$\approx 97\mathrm{\%}$~~97%\approx 97 \% of its capacity upon completion of 200 cycles of operation.
在这项研究中，我们制备了一种新型的 1D 结构铁电陶瓷基异质结纳米纤维，并将其复合成固体聚合物电解质。已采取这一行动来构建界面电场，这反过来又促进了锂盐的解离和快速均匀的沉积。此外，使用静电纺丝技术构建了长程有机/无机界面作为锂离子传输途径。表面的 ${\mathrm{MoSe}}_2$${\mathrm{MoSe}}_2$MoSe_(2)\mathrm{MoSe}_{2} 热液生长进一步增加了比表面积，并提供了界面电场，这是离子解离和传输的新途径，进一步增强了 PVDF-SPE 的性能。BTO-MS 异质结纳米纤维 （BTO-MS HNF） 还可以降低针对电解质和锂金属阴极的界面电势，并削弱 SCL。这些协同效应创造了卓越的性能。LFP/PVBM/Li 电池在 5 C $110.7\mathrm{mAh}{\mathrm{g}}^{-1}$$110.7\mathrm{mAh}{\mathrm{g}}^{-1}$110.7mAhg^(-1)110.7 \mathrm{mAh} \mathrm{g}^{-1} 时的容量为 5 C，循环 1500 $82.6\mathrm{\%}$$82.6\mathrm{\%}$82.6%82.6 \% 次后容量保持率。与 PVBM 组装的 LFP/Li 软包电池在完成 200 次运行循环后展示了其容量并保持 $127.8\mathrm{mAh}{\mathrm{g}}^{-1}$$127.8\mathrm{mAh}{\mathrm{g}}^{-1}$127.8mAhg^(-1)127.8 \mathrm{mAh} \mathrm{g}^{-1} $\approx 97\mathrm{\%}$$\approx 97\mathrm{\%}$~~97%\approx 97 \% 了其容量。

BTO-MS HNFs with a molar ratio of BTO to MS of 1:1.3 were synthesized via a three-step process, which comprising electrospinning, annealing, and hydrothermal treatment BTO-MS heterostructured nanofibers (HNFs) with a molar ratio of BTO to MS of 1:1.3 were synthesized via a three-step process, comprising electrospinning, annealing and hydrothermal treatment (Figure S1, Supporting Information). As illustrated in Figure 1a-c,
BTO 与 MS 摩尔比为 1：1.3 的 BTO-MS HNF 是通过三步工艺合成的，包括静电纺丝、退火和水热处理 BTO 与 MS 摩尔比为 1：1.3 的 BTO-MS 异质结构纳米纤维 （HNF） 是通过静电纺丝、退火和水热处理三步工艺合成的（图 S1，支持信息）。如图 1a-c 所示，

Figure 1. Characterization of ferroelectric BTO-MS HNFs. a-c) Scanning electron microscope (SEM) images of precursor $\mathrm{Ba}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2-\mathrm{Ti}{\left({\mathrm{OC}}_4{\mathrm{H}}_9\right)}_4$$\mathrm{Ba}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2-\mathrm{Ti}{\left({\mathrm{OC}}_4{\mathrm{H}}_9\right)}_4$Ba(C_(2)H_(3)O_(2))_(2)-Ti(OC_(4)H_(9))_(4)\mathrm{Ba}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}-\mathrm{Ti}\left(\mathrm{OC}_{4} \mathrm{H}_{9}\right)_{4} -PVP nanofibrous membranes, BTO NFs and BTO-MS HNF. d) Fabrication process of BTO-MS HNFs. e) TEM images of BTO NFs, f) MS NPs, and g) BTO-MS HNF. h) Schematic representation of the mechanism by which BTO-MS HNF promotes dissociation of lithium salts, modulates the solvation structure of ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+}, facilitates homogeneous deposition of lithium ions, and provides a robust SEI .
图 1.铁电 BTO-MS HNF 的表征。a-c） 前驱体 $\mathrm{Ba}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2-\mathrm{Ti}{\left({\mathrm{OC}}_4{\mathrm{H}}_9\right)}_4$$\mathrm{Ba}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2-\mathrm{Ti}{\left({\mathrm{OC}}_4{\mathrm{H}}_9\right)}_4$Ba(C_(2)H_(3)O_(2))_(2)-Ti(OC_(4)H_(9))_(4)\mathrm{Ba}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}-\mathrm{Ti}\left(\mathrm{OC}_{4} \mathrm{H}_{9}\right)_{4} -PVP 纳米纤维膜、BTO NFs 和 BTO-MS HNF 的扫描电子显微镜 （SEM） 图像。d） BTO-MS HNF 的制造过程。e） BTO NF 的 TEM 图像，f） MS NP 和 g） BTO-MS HNF。h） BTO-MS HNF 促进锂盐解离、调节锂盐的溶剂化结构 ${\mathrm{Li}}^{+}$${\mathrm{Li}}^{+}$Li^(+)\mathrm{Li}^{+} 、促进锂离子均匀沉积并提供稳健的 SEI 的机制示意图。

BTO-MS HNFs are derived by calcining smooth precursor nanofibers to form porous barium titanate (BTO) nanoscale ceramic fibers, followed by in situ hydrothermal formation of molybdenum diselenide (MS). Figure 1d provides a detailed description of the material transformations that occur during the synthesis process. The fabrication of composite solid electrolytes (CSEs) entailed the incorporation of BTO-MS HNFs into a PVDF matrix (denoted as PVBM) through solution casting, resulting in the formation of smooth and flexible surfaces (Figure S2, Supporting Information). Transmission electron microscopy (TEM) and high-resolution TEM (HR-TEM) images (Figure 1e-g; Figure S3, Supporting Information) reveal the microcrystalline structures of the BTO nanofibers, MS nanoparticles, and BTO-MS heterostructured nanofibers. The calcined BTO nanofibers exhibit diameters of $\approx 240\mathrm{nm}$$\approx 240\mathrm{nm}$~~240nm\approx 240 \mathrm{~nm} and a high aspect ratio, which is tunable via precursor solution composition and electrospinning voltage. HR-TEM measurements indicate a lattice spacing of 0.2801 nm ,
BTO-MS HNF 是通过煅烧光滑的前驱体纳米纤维形成多孔钛酸钡 （BTO） 纳米级陶瓷纤维，然后原位水热生成二硒化钼 （MS） 而获得的。图 1d 提供了合成过程中发生的材料转变的详细描述。复合固体电解质 （CSE） 的制造需要通过固溶铸造将 BTO-MS HNF 掺入 PVDF 基体（表示为 PVBM）中，从而形成光滑和灵活的表面（图 S2，支持信息）。透射电子显微镜 （TEM） 和高分辨率 TEM （HR-TEM） 图像（图 1e-g;图 S3，支持信息）揭示了 BTO 纳米纤维、MS 纳米颗粒和 BTO-MS 异质结构纳米纤维的微晶结构。煅烧 BTO 纳米纤维具有直径和高 $\approx 240\mathrm{nm}$$\approx 240\mathrm{nm}$~~240nm\approx 240 \mathrm{~nm} 纵横比，可通过前驱体溶液成分和静电纺丝电压进行调整。HR-TEM 测量表明晶格间距为 0.2801 nm，
corresponding to the BTO (111) plane, while the MS nanoparticles (NPs) display a lattice spacing of 0.2348 nm , consistent with the (103) plane. The BTO-MS heterostructured nanofibers (HNs) exhibit clearly defined heterogeneous structures with MS NPs grown in situ on the BTO nanofibers (Figure 1g). HR-TEM images confirm lattice spacings at the interfaces of 0.2763 nm (BTO (100) face) and 0.2125 nm (MS (006) face). Elemental mapping (Figures S4-S6, Supporting Information) corroborates the homogeneous dispersion of the components and attests to the high purity of the material.
对应于 BTO （111） 平面，而 MS 纳米颗粒 （NP） 显示 0.2348 nm 的晶格间距，与 （103） 平面一致。BTO-MS 异质结构纳米纤维 （HN） 表现出明确定义的异质结构，其中 MS NP 在 BTO 纳米纤维上原位生长（图 1g）。HR-TEM 图像确认了 0.2763 nm（BTO （100） 面）和 0.2125 nm（MS （006） 面）界面处的晶格间距。元素映射（图 S4-S6，支持信息）证实了组分的均匀分散，并证明了材料的高纯度。

Figure 2a and Figure S7 (Supporting Information) shows the X-ray diffraction (XRD) patterns for BTO, MS, and BTOMS. The diffraction intensities of MS nanoparticles overlap with those of BTO nanofibers, with the weaker MS peaks being less discernible, suggesting highly dispersed monolayer and multilayer structures. An additional peak at $2\theta ={26.5}^{\circ }$$2\theta ={26.5}^{\circ }$2theta=26.5^(@)2 \theta=26.5^{\circ} is attributed to ${\mathrm{BaMoO}}_4$${\mathrm{BaMoO}}_4$BaMoO_(4)\mathrm{BaMoO}_{4} formation during the hydrothermal
图 2a 和图 S7（支持信息）显示了 BTO、MS 和 BTOMS 的 X 射线衍射 （XRD） 图样。MS 纳米颗粒的衍射强度与 BTO 纳米纤维的衍射强度重叠，较弱的 MS 峰不太明显，表明高度分散的单层和多层结构。另一个峰值 $2\theta ={26.5}^{\circ }$$2\theta ={26.5}^{\circ }$2theta=26.5^(@)2 \theta=26.5^{\circ} 归因于 ${\mathrm{BaMoO}}_4$${\mathrm{BaMoO}}_4$BaMoO_(4)\mathrm{BaMoO}_{4} 热液过程中的形成