A Ternary Composite with Medium Adsorption Confirms Good Reversibility of Li-Se Batteries

Yi Li; Zhao Li; Liang Yue; Yi Zhang; Shuang Liu; Yubin Niu; Sam Zhang; Maowen Xu

doi:10.1002/advs.202206962

A Ternary Composite with Medium Adsorption Confirms Good Reversibility of Li-Se Batteries

Adv Sci (Weinh). 2023 Jun;10(16):e2206962. doi: 10.1002/advs.202206962. Epub 2023 Apr 14.

Authors

Yi Li^{1

2}, Zhao Li³, Liang Yue^{1

2}, Yi Zhang^{1

2}, Shuang Liu^{1

2}, Yubin Niu^{1

2}, Sam Zhang^{1

2

4}, Maowen Xu^{1

2}

Affiliations

¹ Key Lab for Advanced Materials and Clean Energies of Technologies, Southwest University, Chongqing, 400715, P. R. China.
² School of Materials and Energy, Southwest University, Chongqing, 400715, P. R. China.
³ National Engineering Research Center of Light Alloy Net Forming & Shanghai Key Laboratory of Hydrogen Science, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
⁴ Center for Advanced Thin Films and Devices, School of Materials and Energy, Southwest University, Chongqing, 400715, P. R. China.

Abstract

For Li-Se batteries, cathode using carbonaceous hosts to accommodate Se performed modestly, whereas those applying metallic compounds with stronger chemical adsorption exhibited even more rapid capacity decay, the intrinsic reasons for which are still not clear. Herein, it is found that Se tends to precipitate on the surface of the electrode during cycling, and the precipitation speed depends on the polarization degree of the host. A further enhanced adsorption does not certainly generate better electrochemical activity, since hosts with overhigh adsorption ability are hard to desorb polyselenides, leading to catalyst passivation and rapid capacity decay. These findings encourage us to design a ternary anatase/rutile/titanium nitride (aTiO₂ /rTiO₂ /TiN@C) composite host, integrating good adsorption of TiO₂ and rapid electron transport ability of TiN, and introducing rutile to weaken overall adsorption. The aTiO₂ /rTiO₂ /TiN@C composite with medium adsorption not only avoids rapid loss of active substances in electrolyte but also slows down the precipitation speed of Se. As a result, the aTiO₂ /rTiO₂ /TiN@C/Se electrode delivered good rate capability(154 mA h g^-1 at 20 C) and good cycling stability(a low decay of 0.024% per cycle within 500 cycles at 2 C).

Keywords: cathode-electrolyte interface films; lithium-selenium batteries; polyselenides adsorption/desorption; reversibility.

Abstract

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