With the shortage of lithium resources,sodiumion batteries(SIBs)are considered one of the most promising candidates for lithium-ion batteries.P2-type and O3-type layered oxides are one of the few cathodes that can acc...With the shortage of lithium resources,sodiumion batteries(SIBs)are considered one of the most promising candidates for lithium-ion batteries.P2-type and O3-type layered oxides are one of the few cathodes that can access high energy density.However,they usually exhibit structural change,capacity decay,and slow Na ion kinetic.Herein,we present layered ternary-phase cathodes with P2,P3 and O3 phases by a lattice doping strategy,which is demonstrated by X-ray diffraction(XRD)refinement.Combining the characteristics of P2,P3 and O3 phases,the layered composites show performance improvement during long-term battery cycling.In particular,Na_(0.7)Li_(0.1)Co_(0.3-)Fe_(0.3)Mn_(0.3)O_(2)(NLCFM)delivers a reversible capacity of120.1 mAh·g^(-1)at 0.1C(1.0C=175 mA·g^(-1))with a superior capacity retention of 72.5%after 1000 cycles at10.0C.This work offers insights into the development of advanced cathode materials for SIBs.展开更多
Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient ele...Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient elec-trons.Here,we report the modulation of electrode/elec-trolyte interface to yield excellent rate performance by creating cross-linked conducting carbon network in LiFePO_(4)/C cathode material.Such conducting networks inhibit agglomeration and growth of LiFePO_(4)/C primary particles and hence lead to a short Li^(+)diffusion pathway.Furthermore,it also offers fast electron transmission rate and efficient electron for Li storage in the LiFePO_(4)sheath.The LiFePO_(4)/C with carbon nanotubes(CNTs)delivers a discharge capacity of 150.9 mAh·g^(-1) at 0.1C(initial Coulombic efficiency of 96.4%)and an enhanced rate capability(97.2 mAh·g^(-1) at 20.0C).Importantly,it exhi-bits a high cycle stability with a capacity retention of 90.3%even after 800 cycles at 5.0C(0.85 A·g^(-1)).This proposed interface design can be applied to a variety of battery electrodes that face challenges in electrical contact and ion transport.展开更多
基金financially supported by Guangxi Natural Science Foundation(No.2021GXNSFDA075012)the National Natural Science Foundation of China(Nos.U20A20249 and 22169004)+2 种基金the Natural Science Fund of Huanggang Normal University for Young Scholars(No.2014019203)the Special Fund for Guangxi Distinguished Expertthe Innovation Project of Guangxi Graduate Education(No.JGY2022031)。
文摘With the shortage of lithium resources,sodiumion batteries(SIBs)are considered one of the most promising candidates for lithium-ion batteries.P2-type and O3-type layered oxides are one of the few cathodes that can access high energy density.However,they usually exhibit structural change,capacity decay,and slow Na ion kinetic.Herein,we present layered ternary-phase cathodes with P2,P3 and O3 phases by a lattice doping strategy,which is demonstrated by X-ray diffraction(XRD)refinement.Combining the characteristics of P2,P3 and O3 phases,the layered composites show performance improvement during long-term battery cycling.In particular,Na_(0.7)Li_(0.1)Co_(0.3-)Fe_(0.3)Mn_(0.3)O_(2)(NLCFM)delivers a reversible capacity of120.1 mAh·g^(-1)at 0.1C(1.0C=175 mA·g^(-1))with a superior capacity retention of 72.5%after 1000 cycles at10.0C.This work offers insights into the development of advanced cathode materials for SIBs.
基金financially supported by the National Natural Science Foundation of China (Nos. 51902108, 51762006 and 51774100)Guangxi Innovation Driven Development Subject (No. GUIKE AA19182020)+2 种基金Guangxi Natural Science Foundation (Nos. 2018GXNSFBA138002 and 2021GXNSFDA075 012)Guangxi Technology Base and Talent Subject (No. GUIKE AD18126001)Special Fund for Guangxi Distinguished Expert。
文摘Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient elec-trons.Here,we report the modulation of electrode/elec-trolyte interface to yield excellent rate performance by creating cross-linked conducting carbon network in LiFePO_(4)/C cathode material.Such conducting networks inhibit agglomeration and growth of LiFePO_(4)/C primary particles and hence lead to a short Li^(+)diffusion pathway.Furthermore,it also offers fast electron transmission rate and efficient electron for Li storage in the LiFePO_(4)sheath.The LiFePO_(4)/C with carbon nanotubes(CNTs)delivers a discharge capacity of 150.9 mAh·g^(-1) at 0.1C(initial Coulombic efficiency of 96.4%)and an enhanced rate capability(97.2 mAh·g^(-1) at 20.0C).Importantly,it exhi-bits a high cycle stability with a capacity retention of 90.3%even after 800 cycles at 5.0C(0.85 A·g^(-1)).This proposed interface design can be applied to a variety of battery electrodes that face challenges in electrical contact and ion transport.
