In Situ Coupling of Colloidal Silica and Li Salt Anion toward Stable Li Anode for Long-Cycle-Life Li-O2 Batteries

Abstract

An electrolyte regulation strategy via in situ coupling of CF 3 SO 3 À and hydrophobic silica colloidal nanoparticles through electrostatic interaction is achieved. The seed crystal effect as well as anion-fixed and solid-like rheological properties can effectively prevent dendrites. The lower diffusion coefficient and hydrophobic property of nanosilica can lead to nearly 980-fold anticorrosion results. Consequently, the symmetrical batteries display 700 h of life with 30 mV overpotential and 45-fold lower R SEI . Moreover, a 550-cycle anodic life is achieved in Li-O 2 batteries with 10 wt % HSCE.

Electrode Protection in High-Efficiency Li–O2 Batteries

“… 68 (h) Schematic of colloidal silica and Li salt anion triggered stable Li anode. 9 (i) Schematic representation of hybrid solid electrolyte enabled dendrite-free lithium anode. 69 Images reproduced or adapted with permission from refs ( 9 , 22 , 61 , and 64 − 69 ).…”

“…For example, the addition of 10 wt % hydrophobic silica nanoparticle in 1 M LiCF 3 SO 3 /tetraethylene glycol dimethyl ether (TEGDME) electrolyte could prevent the Li metal anode from irregular dendrite growth and serious corrosion in Li–O 2 batteries ( Figure 3 h). 9 Further, boric acid (BA) was proved to be an efficient additive in facilitating the generation of a continuous and durable SEI layer, more than six-times prolonging of the lifetime of the Li–O 2 batteries. 84 However, besides the additive, the SEI formation is also accompanied by the Li salt and solvent decomposition, resulting in the SEI with multiple components and inhomogeneous distribution.…”

“…Moreover, the dendrite growth and infinite volume change of metal Li anode further deteriorate the lifetime of Li–O 2 batteries. 8 , 9 All these issues make the achievable energy density and the cycle life of Li–O 2 batteries have a big disparity to the theoretical values and are far away from practical applications. Therefore, in the past decade, significant efforts have been invested to unlock the full potential of the Li–O 2 battery as well as to promote it suitable for real-world implementation.…”

Efforts towards Practical and Sustainable Li/Na‐Air Batteries

“…Recently, we adopted the rheological properties of the electrolyte by adding 10% hydrophobic silica to make it solid‐like (Figure 3l). [ 30 ] Due to the electrostatic interaction between CF 3 SO 3 – and silica particles, the viscosity of the optimized electrolyte was increased for 980‐fold, thus the diffusion of H 2 O or other contaminants was much slower. The Li anode in this Li‐O 2 battery achieved a long life of 550 cycles, showing good protection effect.…”

Overcharge for Reviving Failed Li-O2 Batteries

“…Traditional methods to extend the life of Li-O 2 batteries include cathode material engineering [3][4][5] , electrolyte design [6][7][8][9][10][11] , anode optimization 12,13 , and interphase tuning [14][15][16][17] . However, the performance of Li-O 2 batteries is still far from satisfactory.…”