Electrode structure deterioration and unstable solid-electrolyte-interphase (SEI) are crucial issues hindering the application of silicon anode in high energy lithium-ion batteries.^[1-3] Here, we report a simple way to construct a stable silicon anode enabled by pouring branched polyurethane gel that comprise ion-conductive ethylene oxide (EO) soft segment into electrode. This tough gel conformably coated on the electrode components and strongly bonded them together through the chemical bonding and hydrogen bonding, forming a robust electrode. Additionally, it provides mechanical and chemical protection while Li⁺ transport, behaving as an artificial SEI layer. The harness of bifunctional gel polymer lead to a significant improvement of electrochemical performance with an capacity retention of 90% within 150 cycles and achieve a high areal capacity over 4 mAh/cm² when micro-sized silicon-based materials was evaluated.

References

[1] C.-M. Park, J.-H. Kim, H. Kim, H.-J. Sohn, Chem. Soc. Rev. 2010, 39, 3115.

[2] J. Song, M. Zhou, R. Yi, T. Xu, M. L. Gordin, D. Tang, Z. Yu, M. Regula, D. Wang, Adv. Funct. Mater. 2014, 24, 5904.

[3] J. Song, Z. Yu, M. L. Gordin, D. Wang, Nano Lett. 2016, 16, 864.