Spatially-confined lithiation–delithiation in highly dense nanocomposite anodes towards advanced lithium-ion batteries

Abstract

Spatially-confined electrochemical reactions are firstly realized in a highly dense nanocomposite anode for high performance lithium ion batteries. The spatially-confined 10 lithiation/delithiation effectively avoids inter-cluster migration and perfectly keeps full structure integrity. Large reversible capacity, high rate capability and superior cycle stability are achieved simultaneously. This spatially-confined lithiation/delithiation offers novel insight to enhance cycling 15 performance of high capacity anode materials.

Cooperation of Fe 2 O 3 @C and Co 3 O 4 /C subunits enhances the cyclic stability of Fe 2 O 3 @C/Co 3 O 4 electrodes for lithium‐ion batteries

“…The encircled porous carbon layer alleviates the structural strain and ensures the stability of Fe 2 O 3 during the repeated Li + insertion/extraction of Li + ions; moreover, the network Fe connected with the conductive carbon layer supports electron transfer, facilitating the full redox reaction. As reported in the literature, the existence of the matrix confining the cation diffusion during cycles is crucial for the conversion mechanism electrode. In a Co 3 O 4 /C unit, a porous carbon layer loaded with Co 3 O 4 nanoparticles is found to have a promotional role due to its good electronic conductivity and capability of confining Co 3 O 4 aggregation and diffusion by effect of its porosity.…”

Review—Promises and Challenges of In Situ Transmission Electron Microscopy Electrochemical Techniques in the Studies of Lithium Ion Batteries

“…The excellent spatial-confining effect of CNTs on the aggregation and coarsening of the formed Fe@Li 2 O nanograins upon charging was observed after encapsulation of Fe 2 O 3 NPs inside CNTs by Yu, et al 53,174 The in situ TEM observations clearly shows that the prelithiated Fe 2 O 3 both on the outer and inner surface of the CNTs experienced the same structural transformations upon charging/discharging, while the size of the Fe@ Li 2 O nanograins produced on the outside of the CNTs reaches around 6 nm, which is six times bigger than those produced on the inside of the CNTs. This means that the confinement of the CNTs inhibits the growth and accumulation of the Fe@Li 2 O nanograins upon charging, leading to highly improved interfacial lithium storage reactions, good electrochemical reversibility, and structural stability.…”

“…73,96 By in situ TEM with an electrochemical liquid cell, the inhomogeneous lithiation of a Au electrode, dendritic growth of lithium metal, electrolyte decomposition, and formation of SEI were observed by Zeng, et al 96 Jiang, et al, proposed an uncommon and highly dense SnO 2 -Fe 2 O 3 -Li 2 O nanocomposite anode with a unique spatiallyconfined lithiation-delithiation reaction. 174 The authors stated that they successfully removed the cycling failure of the high-capacity anode by restraining the migration of atoms upon lithiation/delithiation. The newly-designed electrode takes full advantage of nanomaterials in volume-variation and Li-ion diffusion, and remains around 6034.5 mA·h·cm −3 after two hundred extremely stable cycles, which is the highest volumetric capacity, even after long cycling, at present.…”

Silkworm Excrement Derived In‐situ Co‐doped Nanoporous Carbon as Confining Sulfur Host for Lithium Sulfur Batteries

“…According to the BET and TEM results, nano‐sized sulfur particles are uniformly distributed, which are effectively separated by the conductive carbon matrix. Therefore, sulfur can be strict physical confined at their pristine place with little migration, maintaining their structure integrity . Further, enhanced reaction kinetics can be realized owing to the shortened diffusion length for Li‐ions and fast transportation channel for electrons, which is shown in EIS results.…”