A Freestanding 3D Skeleton with Gradationally Distributed Lithiophilic Sites for Realizing Stable Lithium Anodes

Abstract

Li metal anodes are drawing considerable attention owing to their ultrahigh theoretical capacities and low electrochemical reduction potentials. However, their commercialization has been hampered by safety hazards induced by continuous dendrite growth. These issues can be alleviated using the ZnO‐modified 3D carbon‐based host containing carbon nanotubes (CNTs) and carbon felt (CF) fabricated by electroplating in the present study (denoted as ZnO/CNT@CF); the constructed skeleton has lithiophilic ZnO that is gradationally distributed along its thickness. The utilization of an inverted ZnO/CNT@CF‐Li anode obtained by flipping over the carbon skeleton after Li electrodeposition is also reported herein. The synergistic effect of the Li metal and lithiophilic sites reduces the nucleation overpotential, thus inducing Li+ to preferentially deposit inside the porous carbon‐based scaffold. The composite electrode compels Li to grow away from the separator, thereby significantly improving battery safety. A symmetric cell with the inverted ZnO/CNT@CF‐Li electrode operates steadily for 700 cycles at 1 mA cm−2 and 1 mAh cm−2. Moreover, the ZnO/CNT@CF‐Li|S cell exhibits an initial areal capacity of 10.9 mAh cm−2 at a S loading of 10.4 mg cm−2 and maintains a capacity of 3.0 mAh cm−2 after 320 cycles.

Trends in carbon nanotube research and development: A landscape view of emerging applications and materials

“…The length of CNT and their conductivity makes them useful as molecular wires, and their strength could allow them to reduce the expansion and contraction of battery materials during charging/discharging, which leads to component separation and battery failure, or to form a barrier to dendrites, preventing short circuits and their associated hazards. These characteristics motivate the use of CNT in batteries such as (with ZnO and carbon felt) in lithium-ion (Li-ion) battery electrodes resistant to lithium dendrite formation, 69 and materials such as graphene networks, NiCoO2, MnO2, nitrogen-doped carbon, and cobalt-iron metal-organic frameworks in biocompatible and hybrid zinc or in zinc-air batteries. [70][71][72] One feature of note is that battery applications represent a much higher fraction of patent publications compared to journal publications (more journal publications are devoted to CNT-containing sensors than CNTcontaining batteries).…”

Review of Carbon Nanotube Research and Development: Materials and Emerging Applications

“…The length of CNTs and their conductivity makes them useful as molecular wires, and their strength could allow them to reduce the expansion and contraction of battery materials during charging/discharging, which leads to component separation and battery failure, or to form a barrier to dendrites, preventing short circuits and their associated hazards. These characteristics motivate the use of CNTs in batteries such as (with ZnO and carbon felt) in lithium-ion (Li-ion) battery electrodes resistant to lithium dendrite formation, and materials such as graphene networks, NiCoO 2 , MnO 2 , nitrogen-doped carbon, and cobalt–iron metal–organic frameworks in biocompatible and hybrid zinc or in zinc-air batteries. − One feature of note is that battery applications represent a much higher fraction of patent publications compared to journal publications (more journal publications are devoted to CNT-containing sensors than CNT-containing batteries). Many of the patents for batteries originate from China or South Korea; a push to transition from internal combustion to electrical power for transportation, and the large consumer electronic industries in those nations likely motivate battery development and commercialization.…”

Advanced Separator Materials for Enhanced Electrochemical Performance of Lithium–Sulfur Batteries: Progress and Prospects

“…Among these components, the separator plays a critical role in suppressing the migration of polysulfides. When lithium ions migrate to the cathode through the separator, solid sulfur (S 8 ) undergoes a series of redox reactions and is reduced to Li 2 S. 10 Traditional olefinic separators, such as those made from polypropylene (PP) or polyethylene (PE), possess relatively large pore sizes. As a result, polysulfides can easily pass through the separator and reach the surface of the lithium plates.…”