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Highly Elastic Polyrotaxane Binders for Mechanically Stable Lithium Hosts in Lithium‐Metal Batteries
Author(s) -
Yoo DongJoo,
Elabd Ahmed,
Choi Sunghun,
Cho Yunshik,
Kim Jaemin,
Lee Seung Jong,
Choi Seung Ho,
Kwon Taewoo,
Char Kookheon,
Kim Ki Jae,
Coskun Ali,
Choi Jang Wook
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201901645
Subject(s) - materials science , lithium metal , lithium (medication) , vinyl alcohol , anode , carbon nanotube , composite material , electrical conductor , electrode , nanotechnology , lithium battery , polymer , ionic bonding , ion , medicine , chemistry , physics , quantum mechanics , endocrinology
Despite their unparalleled theoretical capacity, lithium‐metal anodes suffer from well‐known indiscriminate dendrite growth and parasitic surface reactions. Conductive scaffolds with lithium uptake capacity are recently highlighted as promising lithium hosts, and carbon nanotubes (CNTs) are an ideal candidate for this purpose because of their capability of percolating a conductive network. However, CNT networks are prone to rupture easily due to a large tensile stress generated during lithium uptake–release cycles. Herein, CNT networks integrated with a polyrotaxane‐incorporated poly(acrylic acid) (PRPAA) binder via supramolecular interactions are reported, in which the ring‐sliding motion of the polyrotaxanes endows extraordinary stretchability and elasticity to the entire binder network. In comparison to a control sample with inelastic binder (i.e., poly(vinyl alcohol)), the CNT network with PRPAA binder can endure a large stress during repeated lithium uptake–release cycles, thereby enhancing the mechanical integrity of the corresponding electrode over battery cycling. As a result, the PRPAA‐incorporated CNT network exhibits substantially improved cyclability in lithium–copper asymmetric cells and full cells paired with olivine‐LiFePO 4 , indicating that high elasticity enabled by mechanically interlocked molecules such as polyrotaxanes can be a useful concept in advancing lithium‐metal batteries.