Realizing a lithium sulfide(Li_(2)S)cathode with both high energy density and a long lifespan requires an innovative cathode design that maximizes electrochemical performance and resists electrode deterioration.Herein...Realizing a lithium sulfide(Li_(2)S)cathode with both high energy density and a long lifespan requires an innovative cathode design that maximizes electrochemical performance and resists electrode deterioration.Herein,a high-loading Li_(2)S-based cathode with micrometric Li_(2)S particles composed of two-dimensional graphene(Gr)and one-dimensional carbon nanotubes(CNTs)in a compact geometry is developed,and the role of CNTs in stable cycling of high-capacity Li–S batteries is emphasized.In a dimensionally combined carbon matrix,CNTs embedded within the Gr sheets create robust and sustainable electron diffusion pathways while suppressing the passivation of the active carbon surface.As a unique point,during the first charging process,the proposed cathode is fully activated through the direct conversion of Li_(2)S into S_(8) without inducing lithium polysulfide formation.The direct conversion of Li_(2)S into S_(8) in the composite cathode is ubiquitously investigated using the combined study of in situ Raman spectroscopy,in situ optical microscopy,and cryogenic transmission electron microscopy.The composite cathode demonstrates unprecedented electrochemical properties even with a high Li_(2)S loading of 10 mg cm^(–2);in particular,the practical and safe Li–S full cell coupled with a graphite anode shows ultra-long-term cycling stability over 800 cycles.展开更多
As electric vehicle(EV)sales grew approximately 50%year-over-year,surpassing 3.2 million units in 2020,the“roaring era”of EV is around the corner.To meet the increasing demand for low cost and high energy density ba...As electric vehicle(EV)sales grew approximately 50%year-over-year,surpassing 3.2 million units in 2020,the“roaring era”of EV is around the corner.To meet the increasing demand for low cost and high energy density batteries,anode-free configuration,with no heavy and voluminous host material on the current collector,has been proposed and further investigated.Nevertheless,it always suffers from several non-negligible“bottlenecks”,such as fragile solid electrolyte interface,deteriorated cycling reversibility,and uncontrolled dendrite formation.Inspired by the“compensatory effect”of some disabled people with other specific functions strengthened to make up for their inconvenience,corresponding quasi-compensatory measures after anode removal,involving dimensional compensation,SEI robustness compensation,lithio-philicity compensation,and lithium source compensation,have been carried out and achieved significant battery performance enhancement.In this review,the chemistry,challenges,and rationally designed“quasi-compensatory effect”associated with anode-free lithium-ion battery are systematically discussed with several possible R&D directions that may aid,direct,or facilitate future research on lithium storage in anode-free configuration essentially emphasized.展开更多
Aim:The authors observed the nostril floor in a gross cadaver specimen histologically and innovated a medially based de-epithelialized flap for nasal base narrowing and nostril sill augmentation.Methods:In cadaver,ful...Aim:The authors observed the nostril floor in a gross cadaver specimen histologically and innovated a medially based de-epithelialized flap for nasal base narrowing and nostril sill augmentation.Methods:In cadaver,fully thick section was taken from the nostril sill at the midpoint of the columella base and ala base,and stained with Masson-Trichrome.In eight patients,circumferential incision along the nostril sill and alar base freed the alar base from the upper lip.At the columellar base,fresh epithelium was shaved on the medial side of the incision line.The widened scar on the upper lip was excised.The de-epithelialized tip of the columellar base was pulled under the medial tip of the alar base flap and sutured tightly.Four anthropometric distances were measured preoperatively and postoperatively.Results:Histologically the nostril sill was composed of thickened dermis.Just below the dermis,the depressor septi nasi muscle ran obliquely,augmenting the nostril sill.The nostril floor width,alar distance,and alar curvature distance decreased on the cleft side after the operation.Conclusion:A medially based de-epithelialized flap narrows the alar base and augments the nostril sill simultaneously,since the de-epithelialized part of the excess skin augments the depressed nostril sill.展开更多
Aim:This study aims to characterize the effects of elastic facelifts using the elasticum suspension technique on the cervical angle and anthropometric distances.Methods:Forty-six patients underwent surgery.Two 4-5 mm ...Aim:This study aims to characterize the effects of elastic facelifts using the elasticum suspension technique on the cervical angle and anthropometric distances.Methods:Forty-six patients underwent surgery.Two 4-5 mm incisions a few centimetres apart were made at sideburn.Through blunt dissection,the deep temporal fascia was approached.An elastic thread(Elasticum®)was anchored to this fascia.A 1.0 cm incision was made just in front of the earlobe.The elastic thread was anchored to the tympanoparotid fascia.Jano needle was passed under the skin surface,as determined by the depth mark of the needle along the cervicomandibular angle,and the elastic threads were looped around the contralateral tympanoparotid fascia.Standard lateral photographs were taken and evaluated.Results:The elasticum suspension significantly decreased the cervical angle(P<0.001,-5.5±9.8%).This procedure significantly decreased the distance from the gonion-gnathion to the labiale inferioris(Gn-Li)(P<0.001,-18.4±25.5%).The ratio of the distance from Gn to the cervical point(Gn-C)to Gn-Li increased significantly(P<0.001,62.8±85.8%)and the ratio of the distance from C to the visible thyroid cartilage(C-T)to Gn-C decreased significantly(P=0.007,-7.1±45.2%).Conclusion:Elasticum suspension may be a satisfactory minimally invasive method for facelifts,brow lifts,and neck lifts.展开更多
基金Korea Institute of Energy Technology Evaluation and Planning,Grant/Award Number:20214000000320Samsung Research Funding&Incubation Center of Samsung Electronics,Grant/Award Number:SRFC-MA1901-06。
文摘Realizing a lithium sulfide(Li_(2)S)cathode with both high energy density and a long lifespan requires an innovative cathode design that maximizes electrochemical performance and resists electrode deterioration.Herein,a high-loading Li_(2)S-based cathode with micrometric Li_(2)S particles composed of two-dimensional graphene(Gr)and one-dimensional carbon nanotubes(CNTs)in a compact geometry is developed,and the role of CNTs in stable cycling of high-capacity Li–S batteries is emphasized.In a dimensionally combined carbon matrix,CNTs embedded within the Gr sheets create robust and sustainable electron diffusion pathways while suppressing the passivation of the active carbon surface.As a unique point,during the first charging process,the proposed cathode is fully activated through the direct conversion of Li_(2)S into S_(8) without inducing lithium polysulfide formation.The direct conversion of Li_(2)S into S_(8) in the composite cathode is ubiquitously investigated using the combined study of in situ Raman spectroscopy,in situ optical microscopy,and cryogenic transmission electron microscopy.The composite cathode demonstrates unprecedented electrochemical properties even with a high Li_(2)S loading of 10 mg cm^(–2);in particular,the practical and safe Li–S full cell coupled with a graphite anode shows ultra-long-term cycling stability over 800 cycles.
基金This work was supported by the Global Frontier R&D Programme(2013M3A6B1078875)of the Center for Hybrid Interface Materials(HIM)funded by the Ministry of Science,ICT&Future Planningby the Human Resources Development program(No.20184010201720)of a Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Ministry of Trade,Industry,and Energy of the Korean government.
文摘As electric vehicle(EV)sales grew approximately 50%year-over-year,surpassing 3.2 million units in 2020,the“roaring era”of EV is around the corner.To meet the increasing demand for low cost and high energy density batteries,anode-free configuration,with no heavy and voluminous host material on the current collector,has been proposed and further investigated.Nevertheless,it always suffers from several non-negligible“bottlenecks”,such as fragile solid electrolyte interface,deteriorated cycling reversibility,and uncontrolled dendrite formation.Inspired by the“compensatory effect”of some disabled people with other specific functions strengthened to make up for their inconvenience,corresponding quasi-compensatory measures after anode removal,involving dimensional compensation,SEI robustness compensation,lithio-philicity compensation,and lithium source compensation,have been carried out and achieved significant battery performance enhancement.In this review,the chemistry,challenges,and rationally designed“quasi-compensatory effect”associated with anode-free lithium-ion battery are systematically discussed with several possible R&D directions that may aid,direct,or facilitate future research on lithium storage in anode-free configuration essentially emphasized.
基金supported by Inha University(INHA-Research Grant).
文摘Aim:The authors observed the nostril floor in a gross cadaver specimen histologically and innovated a medially based de-epithelialized flap for nasal base narrowing and nostril sill augmentation.Methods:In cadaver,fully thick section was taken from the nostril sill at the midpoint of the columella base and ala base,and stained with Masson-Trichrome.In eight patients,circumferential incision along the nostril sill and alar base freed the alar base from the upper lip.At the columellar base,fresh epithelium was shaved on the medial side of the incision line.The widened scar on the upper lip was excised.The de-epithelialized tip of the columellar base was pulled under the medial tip of the alar base flap and sutured tightly.Four anthropometric distances were measured preoperatively and postoperatively.Results:Histologically the nostril sill was composed of thickened dermis.Just below the dermis,the depressor septi nasi muscle ran obliquely,augmenting the nostril sill.The nostril floor width,alar distance,and alar curvature distance decreased on the cleft side after the operation.Conclusion:A medially based de-epithelialized flap narrows the alar base and augments the nostril sill simultaneously,since the de-epithelialized part of the excess skin augments the depressed nostril sill.
基金supported by Inha University(INHA-Research Grant).
文摘Aim:This study aims to characterize the effects of elastic facelifts using the elasticum suspension technique on the cervical angle and anthropometric distances.Methods:Forty-six patients underwent surgery.Two 4-5 mm incisions a few centimetres apart were made at sideburn.Through blunt dissection,the deep temporal fascia was approached.An elastic thread(Elasticum®)was anchored to this fascia.A 1.0 cm incision was made just in front of the earlobe.The elastic thread was anchored to the tympanoparotid fascia.Jano needle was passed under the skin surface,as determined by the depth mark of the needle along the cervicomandibular angle,and the elastic threads were looped around the contralateral tympanoparotid fascia.Standard lateral photographs were taken and evaluated.Results:The elasticum suspension significantly decreased the cervical angle(P<0.001,-5.5±9.8%).This procedure significantly decreased the distance from the gonion-gnathion to the labiale inferioris(Gn-Li)(P<0.001,-18.4±25.5%).The ratio of the distance from Gn to the cervical point(Gn-C)to Gn-Li increased significantly(P<0.001,62.8±85.8%)and the ratio of the distance from C to the visible thyroid cartilage(C-T)to Gn-C decreased significantly(P=0.007,-7.1±45.2%).Conclusion:Elasticum suspension may be a satisfactory minimally invasive method for facelifts,brow lifts,and neck lifts.