Université de Fribourg

In situ deprotection of polymeric binders for solution‐processible sulfide‐based all‐solid‐state batteries

Lee, Jieun ; Lee, Kyulin ; Lee, Taegeun ; Kim, Hyuntae ; Kim, Kyungsu ; Cho, Woosuk ; Coskun, Ali ; Char, Kookheon ; Choi, Jang Wook

In: Advanced Materials, 2020, p. 2001702

Sulfide‐based all‐solid‐state batteries (ASSBs) have been featured as promising alternatives to the current lithium‐ion batteries (LIBs) mainly owing to their superior safety. Nevertheless, a solution‐based scalable manufacturing scheme has not yet been established because of the incompatible polarity of the binder, solvent, and sulfide electrolyte during slurry preparation. This...

Université de Fribourg

Covalent triazine frameworks incorporating charged polypyrrole channels for high-performance lithium–sulfur batteries

Kim, Jiheon ; Elabd, Ahmed ; Chung, Sung-Yoon ; Coskun, Ali ; Choi, Jang Wook

In: Chemistry of Materials, 2020, vol. 32, no. 10, p. 4185–4193

Organosulfur polymers have emerged as promising electrode materials for lithium– sulfur (Li–S) batteries, mainly because of their ability to incorporate and stabilize high sulfur content. The low ionic and electronic conductivity of these polymers, however, limit their cycling performance at high active mass loadings. Moreover, Li–polysulfide (Li–PS) shuttling, a fatal phenomenon in...

Université de Fribourg

Lithium-salt mediated synthesis of a covalent triazine framework for highly stable lithium metal batteries

Zhou, Tianhong ; Zhao, Yan ; Choi, Jang Wook ; Coskun, Ali

In: Angewandte Chemie International Edition, 2019, vol. 58, no. 47, p. 16795–16799

A new strategy for the synthesis of a covalent triazine framework (CTF‐1) was introduced based on the cyclotrimerization reaction of 1,4‐dicyanobenzene using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) under ionothermal conditions. LiTFSI not only served as a catalyst, but also facilitated the in situ generation and homogeneous distribution of LiF particles across the framework....

Université de Fribourg

A pyrene–poly(acrylic acid)–polyrotaxane supramolecular binder network for high-performance silicon negative electrodes

Cho, Yunshik ; Kim, Jaemin ; Elabd, Ahmed ; Choi, Sunghun ; Park, Kiho ; Kwon, Tae‐woo ; Lee, Jungmin ; Char, Kookheon ; Coskun, Ali ; Choi, Jang Wook

In: Advanced Materials, 2019, p. 1905048

Although being incorporated in commercial lithium‐ion batteries for a while, the weight portion of silicon monoxide (SiOx, x ≈ 1) is only less than 10 wt% due to the insufficient cycle life. Along this line, polymeric binders that can assist in maintaining the mechanical integrity and interfacial stability of SiOx electrodes are desired to realize higher contents of SiOx. Herein, a...

Université de Fribourg

Highly elastic polyrotaxane binders for mechanically stable lithium hosts in lithium‐metal batteries

Yoo, Dong‐Joo ; Elabd, Ahmed ; Choi, Sunghun ; Cho, Yunshik ; Kim, Jaemin ; Lee, Seung Jong ; Choi, Seung Ho ; Kwon, Tae‐woo ; Char, Kookheon ; Kim, Ki Jae ; Coskun, Ali ; Choi, Jang Wook

In: Advanced Materials, 2019, vol. 31, no. 29, p. 1901645

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...

Université de Fribourg

Prospect for supramolecular chemistry in high-energy-density rechargeable batteries

Kwon, Tae-woo ; Choi, Jang Wook ; Coskun, Ali

In: Joule, 2019, vol. 3, no. 3, p. 662–682

The quest for new electrode materials for Li-ion batteries with high energy densities beyond conventional intercalation-based electrodes has gained significant attention due to the increasing demand for advanced portable devices and electric vehicles (EVs). Among various candidates, the most promising electrode materials along this direction are silicon and Li metal for anodes and sulfur for...

Université de Fribourg

The emerging era of supramolecular polymeric binders in silicon anodes

Kwon, Tae-woo ; Choi, Jang Wook ; Coskun, Ali

In: Chemical Society Reviews, 2018, vol. 47, no. 6, p. 2145–2164

Silicon (Si) anode is among the most promising candidates for the next-generation high-capacity electrodes in Li-ion batteries owing to its unparalleled theoretical capacity (4200 mA h g−1 for Li4.4Si) that is approximately 10 times higher than that of commercialized graphitic anodes (372 mA h g−1 for LiC6). The battery community has witnessed substantial advances in research on new...

Université de Fribourg

Perfluoroaryl‐elemental sulfur SNAr chemistry in covalent triazine frameworks with high sulfur contents for lithium–sulfur batteries

Je, Sang Hyun ; Kim, Hyeon Jin ; Kim, Jiheon ; Choi, Jang Wook ; Coskun, Ali

In: Advanced Functional Materials, 2017, vol. 27, no. 47, p. -

In order to address the challenges associated with lithium–sulfur batteries with high energy densities, various approaches, including advanced designs of sulfur composites, electrolyte engineering, and functional separators, are lately introduced. However, most approaches are effective for sulfur cathodes with limited sulfur contents, i.e., <80 wt%, imposing a significant barrier in...