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1. Large‐Scale Manufacturing of Pattern‐Integrated Paper Li‐Ion Microbatteries through Roll‐to‐Roll Flexographic Printing

   https://doi.org/10.1002/admt.202200303  

   Wang, Ying; Cao, Daxian; Sun, Xiao; Ren, Haoze; Ji, Tongtai; Jin, Xiaoning; Morse, Jeffrey; Stewart, Barbara; Zhu, Hongli (May 2022, Advanced Materials Technologies)

   Abstract Electrode architectures significantly influence the electrochemical performance, flexibility, and applications of lithium‐ion batteries (LiBs). However, the conventional bar coating for fabricating electrodes limits the addition of customized architecture or patterns. In this study, as a novel approach, patterns are integrated into electrodes through large‐scale roll‐to‐roll (R2R) flexographic printing. Additionally, flexible, recyclable, and biodegradable paper are innovatively used as a printing substrate during printing LiBs manufacturing, which exhibited superior printability. Moreover, the paper is modified with a thin‐layer Al₂O₃to function as the separator in the printed LiB. The Al₂O₃‐coated paper enables an admirable wettability for printing, excellent mechanical properties for high‐speed R2R manufacturing, and outstanding thermal stability for the safe and stable operation of LiBs. The assembled paper cells exhibit nearly 100% discharge capacity retention after 1000 cycles at 3 C and outstanding rate performance. This work inspires future large‐scale microbatteries manufacturing integrated with high‐resolution architecture designs. 

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2. Evaluating Trans ‐Benzocyclobutene‐Fused Cyclooctene as a Monomer for Chemically Recyclable Polymer

   https://doi.org/10.1002/asia.202201133  

   Su, Hsin‐Wei; Zhou, Junfeng; Yoon, Seiyoung; Wang, Junpeng (January 2023, Chemistry – An Asian Journal)

   Abstract Chemically recyclable polymers offer a promising solution to address the issues associated with the unsustainable use of plastics by converting the traditional linear plastic economy into a circular one. Central to developing chemically recyclable polymers is to identify the appropriate monomers that enable practical conditions for polymerization and depolymerization and ensure useful stability and material properties. Our group has recently demonstrated thattrans‐cyclobutane‐fused cyclooctene (tCBCO) meets the abovementioned requirements and is a promising candidate for developing chemically recyclable polymers. Herein, encouraged by the success withtCBCO, we investigate the thermodynamics of polymerization of a relevant system,trans‐benzocyclobutene‐fused‐cyclooctene, which can be viewed astCBCO with an additional benzene ring. The study shows that introducing an additional benzene ring favors polymerization and disfavors depolymerization, and the effect is predominantly entropic. The benzo‐effect can be leveraged to fine‐tune the thermodynamics of polymerization and depolymerization to facilitate the chemical recycling of polymers. 

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3. Catalyst‐Sidearm‐Induced Stereoselectivity Switching in Polymerization of a Racemic Lactone for Stereocomplexed Crystalline Polymer with a Circular Life Cycle

   https://doi.org/10.1002/anie.201813006  

   Zhu, Jian‐Bo; Chen, Eugene Y. ‐X. (December 2018, Angewandte Chemie International Edition)

   Abstract Construction of robust, stereocomplexed (sc) crystalline material, based on a recently discovered infinitely recyclable polymer system, requires blending of enantiomeric polymer chains produced from respective enantiopure, fused six‐five bicyclic lactones. Herein, the stereoselective polymerization of the racemic monomer by yttrium catalysts bearing tetradentate ligands is reported, where the tethered donor sidearm switches the heteroselectivity of the catalyst to isoselectivity when it is changed from the β‐OMe to β‐NMe₂sidearm. The latter catalyst produces an isotactic stereoblock polymer (P_mup to 0.95) that forms the crystalline sc‐material with aT_mof up to 171 °C. This sc‐material can be fully depolymerized back to rac‐monomer in a quantitative yield and purity, thus establishing its circular life cycle. 

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4. Living Coordination Polymerization of a Six‐Five Bicyclic Lactone to Produce Completely Recyclable Polyester

   https://doi.org/10.1002/anie.201808003  

   Zhu, Jian‐Bo; Chen, Eugene Y. ‐X. (August 2018, Angewandte Chemie International Edition)

   Abstract The development of chemically recyclable polymers promises a closed‐loop approach towards a circular plastic economy but still faces challenges in structure/property diversity and depolymerization selectivity. Here we report the first successful coordination ring‐opening polymerization of 4,5‐trans‐cyclohexyl‐fused γ‐butyrolactone (M1) with lanthanide catalysts at room temperature, producing P(M1) withM_nup to 89 kg mol⁻¹, high thermal stability, and a linear or cyclic topology. The same catalyst also catalyses selective depolymerization of P(M1) back toM1exclusively at 120 °C. This coordination polymerization is also living, enabling the synthesis of well‐defined block copolymer. 

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5. Photocatalytic Ketyl Radical Initiated C _ketyl −C _sp2 /C _sp3 Coupling on ZnIn ₂ S ₄

   https://doi.org/10.1002/chem.202203785  

   Han, Chuang; Han, Guanqun; Habibur_Rahman, Md; Mannodi‐Kanakkithodi, Arun; Sun, Yujie (May 2023, Chemistry – A European Journal)

   Abstract Visible‐light‐driven C−C bond formation utilizing ketyl radical (C_ketyl) species has attracted increasing attention recently, as it provides a direct route for the synthesis of complex molecules. However, the most‐developed homogeneous photocatalytic systems for the generation and utilization of ketyl radicals usually entail noble metal‐based (e. g., Ru and Ir) photosensitizers, which suffer from not only high cost but also potential degradation and hence pose challenges in product separation and purification. In contrast, readily accessible, inexpensive, and recyclable semiconductors represent a class of attractive and alternative photocatalysts but remain much less explored for photocatalytic ketyl radical initiated C−C bond formation. This work demonstrates that a wide range of industrially important chemicals, including substituted chromanes and tertiary alcohols, can be produced on ZnIn₂S₄under visible light irradiation through intramolecular cyclization (C_ketyl−C_sp2) and intermolecular cross‐coupling (C_ketyl−C_sp3) reactions, respectively, using ketyl radicals. A suite of experimental studies aided by computational investigation were carried out to shed light on the mechanistic insights of these two types of ketyl radical initiated C−C coupling reactions on ZnIn₂S₄. 

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