Electrochemical behavior of layered LiNi0.5Mn0.5O2 in LiNO3 aqueous solution and its cyclic fading mechanism in electrolytes with different pH values were investigated. CV results show that LiNi0.5Mn0.5O2 has good ele...Electrochemical behavior of layered LiNi0.5Mn0.5O2 in LiNO3 aqueous solution and its cyclic fading mechanism in electrolytes with different pH values were investigated. CV results show that LiNi0.5Mn0.5O2 has good electrochemical reversible behaviors in 5 mol/L LiNO3 solution. Meanwhile, the electrode in 5 mol/L LiNO3 with pH value of 12 demonstrates the best electrochemical stability. Based on the electrochemical impedance spectroscopy （EIS）, X-ray diffraction （XRD） and scanning electron microscopy （SEM） results, it is proposed that suppressed charge-transfer resistance is the major reason, which is probably ascribed to the more stable electrode surface and less structure change.展开更多
The limitation of areal energy density of rechargeable aqueous hybrid batteries(RAHBs)has been a significant longstanding problem that impedes the application of RAHBs in miniaturized energy storage.Constructing thick...The limitation of areal energy density of rechargeable aqueous hybrid batteries(RAHBs)has been a significant longstanding problem that impedes the application of RAHBs in miniaturized energy storage.Constructing thick electrodes with optimized geometrical properties is a promising strategy for achieving high areal energy density,but the sluggish ion/electron transfer and poor mechanical stability,as well as the increased electrode thickness,itself present well-known problems.In this work,a 3D printing technique is introduced to construct an ultra-thick lithium iron phosphate(LFP)/carboxylated carbon nanotube(CNT)/carboxyl terminated cellulose nanofiber(CNF)composite electrode with uncompromised reaction kinetics for high areal energy density Li–Zn RAHBs.The uniformly dispersed CNTs and CNFs form continuous interconnected 3D networks that encapsulate LFP nanoparticles,guaranteeing fast electron transfer and efficient stress relief as the electrode thickness increases.Additionally,multistage ion diffusion channels generated from the hierarchical porous structure assure accelerated ion diffusion.As a result,LFP/Zn hybrid pouch cells assembled with 3D printed electrodes deliver a well-retained reversible gravimetric capacity of about 143.5 mAh g^(-1) at 0.5 C as the electrode thickness increases from 0.52 to 1.56 mm,and establish a record-high areal energy density of 5.25 mWh cm^(-2) with an impressive utilization of active material up to 30 mg cm^(-2) for an ultra-thick(2.08 mm)electrode,which outperforms almost all reported zinc-based hybrid-ion and single-ion batteries.This work opens up exciting prospects for developing high areal energy density energy storage devices using 3D printing.展开更多
基金Project(21301193)supported by the National Nature Science Foundation of ChinaProject(2013M530356)supported by the China Postdoctoral Science Foundation Funded+1 种基金Project(CUSZC201303)supported by the Scientific Research Foundation of Central South Universitythe Open-End Found for Valuable and Precision Instruments of Central South University
文摘Electrochemical behavior of layered LiNi0.5Mn0.5O2 in LiNO3 aqueous solution and its cyclic fading mechanism in electrolytes with different pH values were investigated. CV results show that LiNi0.5Mn0.5O2 has good electrochemical reversible behaviors in 5 mol/L LiNO3 solution. Meanwhile, the electrode in 5 mol/L LiNO3 with pH value of 12 demonstrates the best electrochemical stability. Based on the electrochemical impedance spectroscopy （EIS）, X-ray diffraction （XRD） and scanning electron microscopy （SEM） results, it is proposed that suppressed charge-transfer resistance is the major reason, which is probably ascribed to the more stable electrode surface and less structure change.
基金supported by the National Natural Science Foundation of China(22005346,51673123,and 51933007)the National Key R&D Program of China(2017YFE0111500)+2 种基金the Program for Featured Directions of Engineering Multidisciplines of Sichuan University(2020SCUNG203)the State Key Laboratory of Polymer Materials Engineering(sklpme2020-1-02)the Fundamental Research Funds for the Central Universities(YJ202118)。
文摘The limitation of areal energy density of rechargeable aqueous hybrid batteries(RAHBs)has been a significant longstanding problem that impedes the application of RAHBs in miniaturized energy storage.Constructing thick electrodes with optimized geometrical properties is a promising strategy for achieving high areal energy density,but the sluggish ion/electron transfer and poor mechanical stability,as well as the increased electrode thickness,itself present well-known problems.In this work,a 3D printing technique is introduced to construct an ultra-thick lithium iron phosphate(LFP)/carboxylated carbon nanotube(CNT)/carboxyl terminated cellulose nanofiber(CNF)composite electrode with uncompromised reaction kinetics for high areal energy density Li–Zn RAHBs.The uniformly dispersed CNTs and CNFs form continuous interconnected 3D networks that encapsulate LFP nanoparticles,guaranteeing fast electron transfer and efficient stress relief as the electrode thickness increases.Additionally,multistage ion diffusion channels generated from the hierarchical porous structure assure accelerated ion diffusion.As a result,LFP/Zn hybrid pouch cells assembled with 3D printed electrodes deliver a well-retained reversible gravimetric capacity of about 143.5 mAh g^(-1) at 0.5 C as the electrode thickness increases from 0.52 to 1.56 mm,and establish a record-high areal energy density of 5.25 mWh cm^(-2) with an impressive utilization of active material up to 30 mg cm^(-2) for an ultra-thick(2.08 mm)electrode,which outperforms almost all reported zinc-based hybrid-ion and single-ion batteries.This work opens up exciting prospects for developing high areal energy density energy storage devices using 3D printing.
