Poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate)(PETG)possesses excellent properties and stability than traditional poly(ethylene terephthalate)(PET).However,the production and application of PETG are ...Poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate)(PETG)possesses excellent properties and stability than traditional poly(ethylene terephthalate)(PET).However,the production and application of PETG are restricted by the expensive monomer(1,4-cyclohexanedimethanol,CHDM).Direct upgrading of waste PET to dimethyl cyclohexane-1,4-dicarboxylate(DMCD)can promote the production of CHDM in large scale.In this work,a bifunctional Ru/UiO-66_(def)-SO_(3)H catalyst was synthesized and utilized in coupled methanolysis(of waste PET to dimethyl terephthalate(DMT))and hydrogenation(of DMT to DMCD)under mild condition.Characterizations revealed that Ru/UiO-66_(def)-SO_(3)H possessed mesopores(dominant channels of 2.72 and 3.44 nm),enlarged surface area(998 m^(2)·g^(–1)),enhanced acidity(580μmol·g^(–1)),and Ru nanoparticles(NPs)dispersed highly(45.1%)compared to those of Ru/UiO-66.These combined advantages could accelerate the methanolysis and hydrogenation reactions simultaneously,promoting the performance of direct upgrading of PET to DMCD in one pot.In particular,the conversion of PET and yield of DMCD over Ru/UiO-66_(def)-SO_(3)H reached 100%and 97.7%at 170℃and 3 MPa H_(2)within 6 h.Moreover,Ru/UiO-66_(def)-SO3H was also capable for the upcycling of waste PET-based products including beverage bottles,textile fiber and packaging film to DMCD.展开更多
Adopting the metalized plastic current collector(MPCC)enhances the safety and specific energy density of lithium-ion batteries(LIBs)but sacrifices the rate capability.The reduced rate capability is customarily ascribe...Adopting the metalized plastic current collector(MPCC)enhances the safety and specific energy density of lithium-ion batteries(LIBs)but sacrifices the rate capability.The reduced rate capability is customarily ascribed to the lower electronic conductivity of MPCC as compared with the metal ones(e.g.,Al and Cu)due to the less metal usage.Here,we demonstrate that the interfacial contact between the current collector(CC)and the active-material layer,rather than the electronic conductivity of CC,accounts for the rate performance of the cells.By introducing a thin carbon coating(~300 nm)onto the surface of MPCC(e.g.,1μm thick aluminum deposited on both sides of 10μm polyethylene terephthalate(PET)film,Al-PET),we reduced the contact resistance between MPCC and cathode materials.Using the carbon-coated Al-PET(C@Al-PET)as CC,the 6.0-Ah graphite/LiCoO_(2)pouch cell delivers significantly improved fast-charge capability and cycling stability,which are identified as the homogenized potential distribution and electrode utilization with multiphysical field simulations.Most importantly,the cell with C@Al-PET CC could still pass the harsh impact test,promising its applications in high-rate LIBs with superior safety.展开更多
文摘Poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate)(PETG)possesses excellent properties and stability than traditional poly(ethylene terephthalate)(PET).However,the production and application of PETG are restricted by the expensive monomer(1,4-cyclohexanedimethanol,CHDM).Direct upgrading of waste PET to dimethyl cyclohexane-1,4-dicarboxylate(DMCD)can promote the production of CHDM in large scale.In this work,a bifunctional Ru/UiO-66_(def)-SO_(3)H catalyst was synthesized and utilized in coupled methanolysis(of waste PET to dimethyl terephthalate(DMT))and hydrogenation(of DMT to DMCD)under mild condition.Characterizations revealed that Ru/UiO-66_(def)-SO_(3)H possessed mesopores(dominant channels of 2.72 and 3.44 nm),enlarged surface area(998 m^(2)·g^(–1)),enhanced acidity(580μmol·g^(–1)),and Ru nanoparticles(NPs)dispersed highly(45.1%)compared to those of Ru/UiO-66.These combined advantages could accelerate the methanolysis and hydrogenation reactions simultaneously,promoting the performance of direct upgrading of PET to DMCD in one pot.In particular,the conversion of PET and yield of DMCD over Ru/UiO-66_(def)-SO_(3)H reached 100%and 97.7%at 170℃and 3 MPa H_(2)within 6 h.Moreover,Ru/UiO-66_(def)-SO3H was also capable for the upcycling of waste PET-based products including beverage bottles,textile fiber and packaging film to DMCD.
基金support of the National Key R&D Program of China(2022YFB3803500)Zhejiang Rouzhen Technology Corp.,Ltd.,and OPPO Mobile Telecommunications Corp.,Ltd.
文摘Adopting the metalized plastic current collector(MPCC)enhances the safety and specific energy density of lithium-ion batteries(LIBs)but sacrifices the rate capability.The reduced rate capability is customarily ascribed to the lower electronic conductivity of MPCC as compared with the metal ones(e.g.,Al and Cu)due to the less metal usage.Here,we demonstrate that the interfacial contact between the current collector(CC)and the active-material layer,rather than the electronic conductivity of CC,accounts for the rate performance of the cells.By introducing a thin carbon coating(~300 nm)onto the surface of MPCC(e.g.,1μm thick aluminum deposited on both sides of 10μm polyethylene terephthalate(PET)film,Al-PET),we reduced the contact resistance between MPCC and cathode materials.Using the carbon-coated Al-PET(C@Al-PET)as CC,the 6.0-Ah graphite/LiCoO_(2)pouch cell delivers significantly improved fast-charge capability and cycling stability,which are identified as the homogenized potential distribution and electrode utilization with multiphysical field simulations.Most importantly,the cell with C@Al-PET CC could still pass the harsh impact test,promising its applications in high-rate LIBs with superior safety.
