Electrospun Li-confinable hollow carbon fibers for highly stable Li-metal batteries

Progress and perspectives on electrospinning techniques for solid‐state lithium batteries

“…Electrospun nanofibers-derived hollow carbon fibers incorporated with lithiophilic Au nanoparticles (Au@HCF) were prepared to serve as the reliable Li host framework. 230 It was found that Au@HCF Au@HCF could mitigate Li dendrite growth on the top surface guide Li plating and stripping to the core space of the structure, thus rendering the stabilized solid-electrolyte interphase layer. Benefitting from these, a high Coulombic efficiency up to 99%-99.9% under 1 mA cm −2 and 2 mAh cm −2 was achieved.…”

Rational Engineering of Anode Current Collector for Dendrite-Free Lithium Deposition: Strategy, Application, and Perspective

“… Hou et al (2019 ) synthesized homogeneously distributed Ag nanoparticles on Cu foil via an electroless plating process for a lithiophilic current collector, which effectively reduced the nucleation overpotential from 240 to 50 mV, realizing uniform lithium nucleation and subsequently stable lithium plating/stripping. Kim et al (2021 ) fabricated a 1D hollow carbon fiber incorporating with lithiophilic Au nanoparticles as lithiophilic nucleation sites on Cu foil (Au@HCF), reducing the current density and confining lithium to mitigate dendrite growth. The Au@HCF achieved CE of 99.9% under 1 mA/cm 2 with 2 mAh/cm 2 lithium plating/stripping ( Figure 2A ).…”

“… (A) Schematic representation of lithium plating on the bare on the Au@ hollow carbon fiber electrodes and STEM image of Au@ hollow carbon fiber and C, N, and Au EDS elemental mapping ( Kim et al, 2021 ). (B) Diagram of the mechanism of polydopamine-induced Li deposition and the SEM images of the PDA-Cu foil (cross view) ( He et al, 2019 ).…”

One-Dimensional Porous Li-Confinable Hosts for High-Rate and Stable Li-Metal Batteries

“…Metallic lithium (Li) has attracted increasing attention as a promising next-generation anode material owing to its attractive properties, such as high theoretical capacity (3860 mAh g –1 ) and low operating potential (−3.04 V vs standard hydrogen electrode). − However, poor Coulombic efficiency (CE) and catastrophic safety issues, mainly originating from the undesirable dendritic Li growth, have impeded its practical applications. To overcome these inherent shortcomings, considerable efforts have been devoted to realizing Li anodes in Li-metal batteries, including the development of three-dimensional (3D) conductive hosts, − functional electrolytes, − protection layers, − and solid electrolytes. − Among them, the 3D structures consisting of Cu nanowires or carbon materials such as graphite, graphene, and carbon nanotubes can reduce the effective current density and store metallic Li in the inner space of the host; the Li dendrite growth and drastic volume expansion during cycling can be largely mitigated in the 3D Li host. ,,, However, despite these advantages, internal short circuits can take place by the preferential Li deposition on the top surface of the structure (i.e., top plating) due to its conductive nature, eventually hindering the use of the bottom region of the host as Li storage space.…”

“…However, the manufacturing process is rather complicated, and metallic Li deposited inside the host would be exposed to the electrolyte, which leads to electrolyte depletion and an increase in the thickness of the solid–electrolyte interphase (SEI) layer. ,,, Moreover, this weak point can act as a fatal issue in the actual pouch-level cell if a lean electrolyte is applied to realize a high-energy-density cell. Conversely, although core–shell structures containing lithiophilic materials such as Ag, Au, and Zn that can store metallic Li inside the host have been introduced to reduce the volume change and the side reactions by preventing direct contact between Li and electrolyte during prolonged cycling, ,, these structural designs also have problems in that it is difficult to easily diffuse Li-ions inside these structures with the carbon shell hindering Li-ion transport especially at high current density conditions, which leads to Li top plating and thus reduces somewhat their capability for storing Li. Therefore, for realizing the practical cell application, it is desirable to develop a Li-confinable host capable of preventing direct contact with the electrolyte by storing Li inside the structure even at practical levels of current densities.…”