Structural evolution of plasma sprayed amorphous Li4Ti5O12 electrode and ceramic/polymer composite electrolyte during electrochemical cycle of quasi-solid-state lithium battery

Abstract

A quasi-solid-state lithium battery is assembled by plasma sprayed amorphous Li4Ti5O12 (LTO) electrode and ceramic/polymer composite electrolyte with a little liquid electrolyte (10 µL/cm2) to provide the outstanding electrochemical stability and better normal interface contact. Scanning Electron Microscope (SEM), Scanning Transmission Electron Microscopy (STEM), Transmission Electron Microscopy (TEM), and Energy Dispersive Spectrometer (EDS) were used to analyze the structural evolution and performance of plasma sprayed amorphous LTO electrode and ceramic/polymer composite electrolyte before and after electrochemical experiments. By comparing the electrochemical performance of the amorphous LTO electrode and the traditional LTO electrode, the electrochemical behavior of different electrodes is studied. The results show that plasma spraying can prepare an amorphous LTO electrode coating of about 8 µm. After 200 electrochemical cycles, the structure of the electrode evolved, and the inside of the electrode fractured and cracks expanded, because of recrystallization at the interface between the rich fluorine compounds and the amorphous LTO electrode. Similarly, the ceramic/polymer composite electrolyte has undergone structural evolution after 200 test cycles. The electrochemical cycle results show that the cycle stability, capacity retention rate, coulomb efficiency, and internal impedance of amorphous LTO electrode are better than traditional LTO electrode. This innovative and facile quasi-solid-state strategy is aimed to promote the intrinsic safety and stability of working lithium battery, shedding light on the development of next-generation high-performance solid-state lithium batteries.

Dendrites‐Free Lithium Metal Anode Enabled by Synergistic Surface Structural Engineering

“…To resolve the above issues, various strategies including solid electrolyte, [ 6–10 ] artificial SEI, [ 11–15 ] and Li host design [ 16–19 ] have been adapted, and they all show certain improvement in the electrochemical performance. Nonetheless, the interfacial resistance between the electrode and solid electrolyte is extremely higher than that of the liquid one, which will deteriorate the electrochemical performance of the cells.…”

“…Moreover, the internal short circuit and safety hazards may be triggered by piercing the separator, especially under high current density and large capacity. [3][4][5] To resolve the above issues, various strategies including solid electrolyte, [6][7][8][9][10] artificial SEI, [11][12][13][14][15] and Li host design [16][17][18][19] have been adapted, and they all show certain improvement in the electrochemical performance. Nonetheless, the interfacial resistance between the electrode and solid electrolyte is extremely higher than that of the liquid one, which will deteriorate the electrochemical performance of the cells.…”

Circumferential Li metal deposition at high rates enabled by the synergistic effect of a lithiophilic and ionic conductive network

“…the surface and boundaries. [34][35][36] Therefore, the introduction of solid electrolyte nanocrystallites in the amorphous carbon as well as a lithiophilic surface to the composite host material is expected to improve the ion conductivity and thus generate a highperformance Li metal anode at high rates. 37 Herein, we report the strategy of constructing a lithiophilic and ionic conductive network to achieve circumferential plating/stripping of Li metal at high rates.…”

A Prelithiation Separator for Compensating the Initial Capacity Loss of Lithium-Ion Batteries

“…The state-of-the-art Li-ion batteries (LIBs) have attracted much attention as one of the dominating energy storage systems due to their high energy density and long cycle life. − Commercial LIBs are composed of lithium-intercalated cathodes including LiCoO 2 , LiFePO 4 , and LiNi 1‑ x ‑ y Co x Mn y O 2 , as well as lithium-free anodes such as graphite. The energy density of LIBs is determined by the amounts of lithium ions intercalated and extracted in the two electrodes. − During the initial charge process, the organic electrolytes decompose and form a layer of solid electrolyte interphase (SEI) on the anode surface, which irreversibly consumes lithium (Li) from cathode materials and causes a low initial Coulombic efficiency (CE). − The formation of SEI on graphite anode brings a permanent loss of 5–20% Li during the first cycle, leading to reduced specific capacity and energy density of LIBs (Figure a). ,, …”