In situ growth of carbon nanomaterials on active substance is a very favorable strategy for the preparation of electrode in lithium-ion batteries with excellent electrochemical performance and high stability.Small-siz...In situ growth of carbon nanomaterials on active substance is a very favorable strategy for the preparation of electrode in lithium-ion batteries with excellent electrochemical performance and high stability.Small-sized TiO_(2) nanoparticles intercalated into carbon nanosheets(CNS@TiO_(2)SNP-600)were successfully synthesized via in-situ polymerization-carbonization method,utilizing layered H_(2)Ti_(4)O_(9)(HTO)as template and benzidine as carbon source.The morphology and size of TiO_(2) are greatly influenced by carbonization temperature.The coin cell with the CNS@TiO_(2)SNP-600 electrode demonstrates a discharge specific capacity of 430.4 mAh·g^(-1) at a current density of 0.1 A·g^(-1),and the capacity retention rate is 88.1%after 100 cycles;and it also displays a high discharge specific capacity of 101.8 mAh·g^(-1) at a high current density of 12.8 A·g^(-1).The excellent electrochemical performances can be ascribed to the capacitance effect originated from the intercalated structure of in-situ grown CNS and TiO_(2) nanoparticles.We believe this type of materials can be widely used in the lithium-ion batteries and other related green chemical fields.展开更多
Volume change during the insertion/extraction of Li+in electrode materials is an important issue to affect the safety and stability of Li-ion batteries.Here,we prepare a near-zero volume change material of COF derived...Volume change during the insertion/extraction of Li+in electrode materials is an important issue to affect the safety and stability of Li-ion batteries.Here,we prepare a near-zero volume change material of COF derived mesh-liked carbon/TiO_(2)(MC/TiO_(2))composite by using a layered TiO_(2)as a template,and a two-dimensional COF material is inserted into the interlayers by the Schiff base polymerization between melamine and terephthalaldehyde,followed by carbonization at 500℃to convert COF to mesh-liked carbon nanosheets.Due to the introduction of mesh-liked carbon nanosheets,the interlayer conductivity of TiO_(2)is improved,and the nanocavities in mesh-liked carbon nanosheets provide additional chambers for the insertion/extraction of Li-ions without any change of the interlayer distance.The MC/TiO_(2)shows a specific capacity of 472.7 mAh/g at a current density of 0.1 A/g,and good specific capacity retention of 65%remains after 1000 cycles at a current of 1 A/g.展开更多
基金supported by the National Natural Science Foundation of China(22062008)the China Scholarship Council(201908360233)the Jiangxi Provincial Department of Science and Technology(GJJ190436,2019KY56)。
文摘In situ growth of carbon nanomaterials on active substance is a very favorable strategy for the preparation of electrode in lithium-ion batteries with excellent electrochemical performance and high stability.Small-sized TiO_(2) nanoparticles intercalated into carbon nanosheets(CNS@TiO_(2)SNP-600)were successfully synthesized via in-situ polymerization-carbonization method,utilizing layered H_(2)Ti_(4)O_(9)(HTO)as template and benzidine as carbon source.The morphology and size of TiO_(2) are greatly influenced by carbonization temperature.The coin cell with the CNS@TiO_(2)SNP-600 electrode demonstrates a discharge specific capacity of 430.4 mAh·g^(-1) at a current density of 0.1 A·g^(-1),and the capacity retention rate is 88.1%after 100 cycles;and it also displays a high discharge specific capacity of 101.8 mAh·g^(-1) at a high current density of 12.8 A·g^(-1).The excellent electrochemical performances can be ascribed to the capacitance effect originated from the intercalated structure of in-situ grown CNS and TiO_(2) nanoparticles.We believe this type of materials can be widely used in the lithium-ion batteries and other related green chemical fields.
基金the National Natural Science Foundation of China(No.21905282)the State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences(No.20190016)。
文摘Volume change during the insertion/extraction of Li+in electrode materials is an important issue to affect the safety and stability of Li-ion batteries.Here,we prepare a near-zero volume change material of COF derived mesh-liked carbon/TiO_(2)(MC/TiO_(2))composite by using a layered TiO_(2)as a template,and a two-dimensional COF material is inserted into the interlayers by the Schiff base polymerization between melamine and terephthalaldehyde,followed by carbonization at 500℃to convert COF to mesh-liked carbon nanosheets.Due to the introduction of mesh-liked carbon nanosheets,the interlayer conductivity of TiO_(2)is improved,and the nanocavities in mesh-liked carbon nanosheets provide additional chambers for the insertion/extraction of Li-ions without any change of the interlayer distance.The MC/TiO_(2)shows a specific capacity of 472.7 mAh/g at a current density of 0.1 A/g,and good specific capacity retention of 65%remains after 1000 cycles at a current of 1 A/g.
