Constructing 3D Porous Current Collectors for Stable and Dendrite‐Free Lithium Metal Anodes

Abstract

Lithium metal batteries (LMBs) are considered promising candidates for the next‐generation rechargeable batteries due to the ultrahigh theoretical specific capacity (3860 mAh g−1) and the lowest negative electrochemical potential (−3.040 V versus the standard hydrogen anode) of lithium metal. However, the practical application of LMBs has been hindered by various serious challenges, especially the low cycling stability of lithium anodes due to the uncontrolled growth of lithium dendrites, unstable solid–electrolyte interphase, and excessive volume change of lithium metal. 3D lithium metal anodes with reduced local current density and alleviated volume expansion can be used to improve the safety performance of LMBs. The design of various 3D structures is therefore critical to achieve high‐performance lithium metal anodes. This review summarizes recent advances of several important 3D porous structures such as foam structures, parallel arrays, interweaved structures, coiled structures, Janus structures, gradient structures, and alloy frameworks for stable and dendrite‐free lithium metal anodes. The constructing strategies and modification methods of 3D lithium metal anodes are discussed in detail. The design and construction of novel 3D porous current collectors are expected to provide promising opportunities for the next‐generation of high‐energy‐density LMBs.

Thermal‐Stable Separators: Design Principles and Strategies Towards Safe Lithium‐Ion Battery Operations

“…Nanopores are pore gaps in the separator, which are formed by interweaving and overlapping countless fibers with diameters of micrometers or nanometers. [56] These pore gaps allow the migration of Li + during the charging and discharging process. [57] Porosity is defined as the ratio of the volume of micropores to the total volume of the separator.…”

Advanced Material Engineering to Tailor Nucleation and Growth towards Uniform Deposition for Anode‐Less Lithium Metal Batteries

“…Modification of the conventional Cu current collector itself without introducing coatings or using other metals or alloys has the advantage of fitting into the existing manufacturing infrastructure for producing Cu foils. A large number of publications have reported current collectors with tailored nanostructured morphology such as 3D porous structures, nanostructured hierarchical hosts, rough etched surfaces, 3D skeleton hosts, and vacancy-derived structures, which can enhance the lithium plating efficiency and significantly extend the cycling life of the ALMBs [47,[49][50][51][52] To explain the mechanistic reasons of the increased lithium plating that are shared among these structures, a key example is given in Figure 5a, which shows the fabrication of a 3D porous Cu foil. The planar Cu foil was initially soaked in an ammonia solution to facilitate selfassembly of Cu(OH) 2 on the Cu foil was dehydrated to produce CuO, and further reductions were made to provide porous Cu as the porous current collector.…”

“…Similar ideas increasing surface and decreasing localized ion flux with various unique 3D structures were shown in various publications. [48][49][50][51][52] For instance, Tang et al prepared a 3D ordered microporous Cu current collector via a colloidal template method combined with electrochemical deposition. Similarly, due to the large surface area as well its structure for the lithium to deposit inside the porous structures.…”

Fabrication of a 3D Porous Silver Wire Based on a Template-Assisted Electroless Deposition Method

“…1,10 Supercapacitors and batteries need porous structures to load more electroactive materials, 3,11,12 and the porous nature and high surface area of the current collector can also improve the uniformity of ion insertion and release during charging and discharging, as well as the ability for collecting electrons. 13,14 The porous structure enables the catalyst to have a large specific surface area to expose more active sites, which is favorable for the accessibility of target molecules involved in a close range. 15,16 To date, lots of research efforts have been devoted to fabricating metal wires with a porous structure of feature size ranging from nanometers to millimeters.…”

“…For many applications, high porosity and a large specific surface area are important for improving the performance of metal wires. For example, the large specific surface area of the porous structure endows electrochemical sensors with higher sensitivity. , Supercapacitors and batteries need porous structures to load more electroactive materials, ,, and the porous nature and high surface area of the current collector can also improve the uniformity of ion insertion and release during charging and discharging, as well as the ability for collecting electrons. , The porous structure enables the catalyst to have a large specific surface area to expose more active sites, which is favorable for the accessibility of target molecules involved in a close range. , …”