Tellurium (Te) is an ideal electrode for potassium ion batteries (PIBs) owing to its excellent electronic conductivity and high volumetric capacity.However,the Te electrode is prone to capacity fading as the shuttle e...Tellurium (Te) is an ideal electrode for potassium ion batteries (PIBs) owing to its excellent electronic conductivity and high volumetric capacity.However,the Te electrode is prone to capacity fading as the shuttle effect.To address this challenge,we propose molecular regulated Se–Te solid solutions on N-doped porous carbon as the PIBs electrode.After optimizing the Se content in Se–Te solid solutions,the resultant SeTe_(6.8) on N-doped porous carbon (SeTe_(6.8)@C) delivered a capacity of over 400 mAh g^(-1) with a flat plateau of 1.0 V at 500 m A g^(-1).It also achieved a superiorly long cycle life,running for more than 1600 cycles (over 7 months with 0.015%degeneration per cycle) at 100 mA g^(-1) and excellent rate performance (179.9 mAh g^(-1) at 10000 mA g^(-1)).This remarkable electrochemical energy storage of the Te electorde likely arises from suppression of the shuttle effect after doping the Te with strongly electronegative Se atoms (forming K_(s)Te_(3) which is not easily soluble in electrolyte).This study presents a fresh approach for designing and developing ultra-stable Te-based electrodes for PIBs and beyond.展开更多
The Discrete Variational Xα Method DV-Xα with an embeded cluster scheme was used to investigate electronic structure, energy levels, charge distribution and chemical bonding in p-type thermoelectric ceramics :Sb2Te3...The Discrete Variational Xα Method DV-Xα with an embeded cluster scheme was used to investigate electronic structure, energy levels, charge distribution and chemical bonding in p-type thermoelectric ceramics :Sb2Te3-Bi2Te3-Sb2Se3. The results obtained are in agreement with experiment ones, which are instructive to material design.展开更多
基金inancially supported by National Nature Science Foundation of China (U20A20247 and 51922038)Hunan Natural Science Foundation (2019JJ40031)+1 种基金Open Fund program for University Innovation Platform of Hunan Province (20K026)the Fundamental Research Funds for the Central Universities。
文摘Tellurium (Te) is an ideal electrode for potassium ion batteries (PIBs) owing to its excellent electronic conductivity and high volumetric capacity.However,the Te electrode is prone to capacity fading as the shuttle effect.To address this challenge,we propose molecular regulated Se–Te solid solutions on N-doped porous carbon as the PIBs electrode.After optimizing the Se content in Se–Te solid solutions,the resultant SeTe_(6.8) on N-doped porous carbon (SeTe_(6.8)@C) delivered a capacity of over 400 mAh g^(-1) with a flat plateau of 1.0 V at 500 m A g^(-1).It also achieved a superiorly long cycle life,running for more than 1600 cycles (over 7 months with 0.015%degeneration per cycle) at 100 mA g^(-1) and excellent rate performance (179.9 mAh g^(-1) at 10000 mA g^(-1)).This remarkable electrochemical energy storage of the Te electorde likely arises from suppression of the shuttle effect after doping the Te with strongly electronegative Se atoms (forming K_(s)Te_(3) which is not easily soluble in electrolyte).This study presents a fresh approach for designing and developing ultra-stable Te-based electrodes for PIBs and beyond.
文摘The Discrete Variational Xα Method DV-Xα with an embeded cluster scheme was used to investigate electronic structure, energy levels, charge distribution and chemical bonding in p-type thermoelectric ceramics :Sb2Te3-Bi2Te3-Sb2Se3. The results obtained are in agreement with experiment ones, which are instructive to material design.
