The preparation of LiNi_(0.8)Co_(0.2)O_2 was discussed by the multiply sintering method for solid reaction, in which the sintered material was smashed, ground and pelletted between two successive sintering steps. The...The preparation of LiNi_(0.8)Co_(0.2)O_2 was discussed by the multiply sintering method for solid reaction, in which the sintered material was smashed, ground and pelletted between two successive sintering steps. The optimum technological condition was obtained through orthogonal experiments by L_9(3~4) and DTA analysis. The result indicates that the factors of effecting the electrochemical properties of synthesized LiNi_(0.8)Co_(0.2)O_2 are molar ratio of Li/Ni/Co, oxygen pressure, homothermal time, the final sintering temperature in turn according to its importance. The oxygen pressure is reviewed independently and the technological condition is further optimized. With the same method, rare earth element Ce was studied as substitute element of Co and the cathode material of LiNi_(0.95)Ce_(0.05)O_2 with excellent electrochemical properties was prepared. The electrochemical testing results of LiNi_(0.8)Co_(0.2)O_2 and LiNi_(0.95)Ce_(0.05)O_2 experimental batteries show that discharge capacities of them reach 165 and 148 mAh·g^(-1) respectively and the persistence is more than 9 h at 3.7 V.展开更多
Low-cost preparation methods for cathodes with high capacity and long cycle life are crucial for commercializing potassium-ion batteries(PIBs).Presently,the charging/discharging strain that develops in the active cath...Low-cost preparation methods for cathodes with high capacity and long cycle life are crucial for commercializing potassium-ion batteries(PIBs).Presently,the charging/discharging strain that develops in the active cathode material of PIBs causes cracks in the particles,leading to a sharp capacity fade.Here,to abate the strain release and the need for an industrially relevant process,a simple low-cost co-precipitation method for synthesizing yolk-shell P3-type K_(0.5)[Mn_(0.85)Ni_(0.1)Co_(0.05)]O_(2) (YS-KMNC)was reported.As cathode material for PIBs,the YS-KMNC delivers a high reversible capacity(96 mAh g^(-1) at 20 mA g^(-1))and excellent cycle stability(80.5%retention over 400 cycles at a high current density of 200 mA g^(-1)).More importantly,a full battery assembled with the YS-KMNC cathode and a commercial graphite anode exhibits a high operating voltage(0.5-3.4 V)and an excellent cycling performance(84.2%retention for 100 cycles at 100 mA g^(-1)).Considering the low-cost,simple production process and high performance of YS-KMNC cathode,this work could pave the way for the commercial development of PIBs.展开更多
Ni-rich layered oxide with Ni molar content larger than 90%was regarded as an extremely promising candidate for cathode material applied in lithium-ion batteries owing to the significant discharging capacity and low c...Ni-rich layered oxide with Ni molar content larger than 90%was regarded as an extremely promising candidate for cathode material applied in lithium-ion batteries owing to the significant discharging capacity and low cost.Nevertheless,rigorous cycling attenuation resulted from the crystal structure collapse and unstable particles interface deeply restrained the commercial application.In the work,LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2) was modified by Ta5+doping and Li_(2)MnO_(3) covering,which was aimed to enhance the structure stability,defend the electrolyte attacking and promote Li+migration during cycling.The material characterization demonstrated the cathodes after Ta5+doping delivered the larger cell lattice parameters and higher cation ordering,which was helpful to improve the rate property and discharge capacity at low temperature.The Li_(2)MnO_(3) layer was tightly adhered on the outside of LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2),which could effectively relieve the electrolyte attacking and sustain the particle morphology integrity.As a result,2 wt%Li_(2)MnO_(3) coated Li(Ni_(0.90)Co_(0.05)Mn_(0.05))_(0.98)Ta_(0.02)O_(2) exhibited the outstanding discharge capacity of 150.2 mAh g^(−1) at 10.0 large current density and 140.6 mAh g^(−1) at−30℃ as well as the remarkable capacity retention of 93.1%after 300 cycles.Meanwhile,the pouch full batteries obtained by 2 wt%Li_(2)MnO_(3) coated Li(Ni_(0.90)Co_(0.05)Mn_(0.05))_(0.98)Ta_(0.02)O_(2) also showed the more stable storage capability,cyclic property in comparison with bare LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2).展开更多
氟是废旧锂电池回收难以回避的典型杂质元素,其迁移转化行为复杂,制约了高品质正极材料的可控再生制备.本研究通过揭示废旧锂电池在热解、浸出及高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料再生过程中氟的迁移转化规律,为氟的定向调控...氟是废旧锂电池回收难以回避的典型杂质元素,其迁移转化行为复杂,制约了高品质正极材料的可控再生制备.本研究通过揭示废旧锂电池在热解、浸出及高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料再生过程中氟的迁移转化规律,为氟的定向调控及材料的可控再生制备奠定理论基础实验结果表明:热解过程中部分氟(45.71%)以气态热解产物的形式释放到大气中,而另一部分氟(52.34%)则向废三元材料的晶格内发生迁移,并随着湿法浸出溶解到镍钴锰的浸出液中.浸出液中少量的氟会在共沉淀制备前驱体过程中迁移到Ni_(0.9)Co_(0.05)Mn_(0.05)(OH)2前驱体材料,并随着配锂烧结掺杂到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料表面.进一步通过调控氟含量发现,当浸出液中氟浓度控制在0.30 g L^(-1)时,引入到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料中的氟不仅不会引起不利相变,而且能够稳定材料结构,从而有效提升再生高镍材料的循环稳定性(1 C电流密度下循环100圈的容量保持率高达95.7%).因此,本研究不仅揭示了废旧锂电池回收过程中氟的迁移转化行为,而且可控再生制备了高性能氟掺杂高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)正极材料,为废旧锂离子电池回收过程中氟的调控提供了理论依据.展开更多
The poor electrochemical performance of all-solid-state batteries(ASSBs),which is assemblied by Ni-rich cathode and poly(ethylene oxide)(PEO)-based electrolytes,can be attributed to unstable cathodic interface and poo...The poor electrochemical performance of all-solid-state batteries(ASSBs),which is assemblied by Ni-rich cathode and poly(ethylene oxide)(PEO)-based electrolytes,can be attributed to unstable cathodic interface and poor crystal structure stability of Ni-rich cathode.Several coating strategies are previously employed to enhance the stability of the cathodic interface and crystal structure for Ni-rich cathode.However,these methods can hardly achieve simplicity and high efficiency simultaneously.In this work,polyacrylic acid(PAA)replaced traditional PVDF as a binder for cathode,which can achieve a uniform PAA-Li(LixPAA(0<x≤1))coating layer on the surface of single-crystal LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)due to H^(+)/Li^(+)exchange reaction during the initial charging-discharging process.The formation of PAA-Li coating layer on cathode can promote interfacial Li^(+)transport and enhance the stability of the cathodic interface.Furthermore,the partially-protonated surface of SC-NCM83 casued by H^(+)/Li^(+)exchange reaction can restrict Ni ions transport to enhance the crystal structure stability.The proposed SC-NCM83-PAA exhibits superior cycling performance with a retention of 92%compared with that(57.3%)of SC-NCM83-polyvinylidene difluoride(PVDF)after 200 cycles.This work provides a practical strategy to construct high-performance cathodes for ASSBs.展开更多
文摘The preparation of LiNi_(0.8)Co_(0.2)O_2 was discussed by the multiply sintering method for solid reaction, in which the sintered material was smashed, ground and pelletted between two successive sintering steps. The optimum technological condition was obtained through orthogonal experiments by L_9(3~4) and DTA analysis. The result indicates that the factors of effecting the electrochemical properties of synthesized LiNi_(0.8)Co_(0.2)O_2 are molar ratio of Li/Ni/Co, oxygen pressure, homothermal time, the final sintering temperature in turn according to its importance. The oxygen pressure is reviewed independently and the technological condition is further optimized. With the same method, rare earth element Ce was studied as substitute element of Co and the cathode material of LiNi_(0.95)Ce_(0.05)O_2 with excellent electrochemical properties was prepared. The electrochemical testing results of LiNi_(0.8)Co_(0.2)O_2 and LiNi_(0.95)Ce_(0.05)O_2 experimental batteries show that discharge capacities of them reach 165 and 148 mAh·g^(-1) respectively and the persistence is more than 9 h at 3.7 V.
基金financially supported by the National Nature Science Foundation of China (Nos. 51922038, 51672078, 51932011, 51972346, 51802356, and 51872334)the Hunan Outstanding Youth Talents (No. 2019JJ20005)+1 种基金the Innovation-Driven Project of Central South University (No. 2020CX024)AMR acknowledges the financial support from NASA-EPSCo R under Award #NNH17ZHA002C and South Carolina EPSCo R/IDe A Program under Award #18-SR03
文摘Low-cost preparation methods for cathodes with high capacity and long cycle life are crucial for commercializing potassium-ion batteries(PIBs).Presently,the charging/discharging strain that develops in the active cathode material of PIBs causes cracks in the particles,leading to a sharp capacity fade.Here,to abate the strain release and the need for an industrially relevant process,a simple low-cost co-precipitation method for synthesizing yolk-shell P3-type K_(0.5)[Mn_(0.85)Ni_(0.1)Co_(0.05)]O_(2) (YS-KMNC)was reported.As cathode material for PIBs,the YS-KMNC delivers a high reversible capacity(96 mAh g^(-1) at 20 mA g^(-1))and excellent cycle stability(80.5%retention over 400 cycles at a high current density of 200 mA g^(-1)).More importantly,a full battery assembled with the YS-KMNC cathode and a commercial graphite anode exhibits a high operating voltage(0.5-3.4 V)and an excellent cycling performance(84.2%retention for 100 cycles at 100 mA g^(-1)).Considering the low-cost,simple production process and high performance of YS-KMNC cathode,this work could pave the way for the commercial development of PIBs.
基金supported by the Natural Science Research Projects of Colleges and Universities in Jiangsu Province (grant No.24KJA430012)the Open Project Program of Key Laboratories of Fine Chemicals and Surfactants in Sichuan Provincial Universities (grant No.SCFY2203).
文摘Ni-rich layered oxide with Ni molar content larger than 90%was regarded as an extremely promising candidate for cathode material applied in lithium-ion batteries owing to the significant discharging capacity and low cost.Nevertheless,rigorous cycling attenuation resulted from the crystal structure collapse and unstable particles interface deeply restrained the commercial application.In the work,LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2) was modified by Ta5+doping and Li_(2)MnO_(3) covering,which was aimed to enhance the structure stability,defend the electrolyte attacking and promote Li+migration during cycling.The material characterization demonstrated the cathodes after Ta5+doping delivered the larger cell lattice parameters and higher cation ordering,which was helpful to improve the rate property and discharge capacity at low temperature.The Li_(2)MnO_(3) layer was tightly adhered on the outside of LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2),which could effectively relieve the electrolyte attacking and sustain the particle morphology integrity.As a result,2 wt%Li_(2)MnO_(3) coated Li(Ni_(0.90)Co_(0.05)Mn_(0.05))_(0.98)Ta_(0.02)O_(2) exhibited the outstanding discharge capacity of 150.2 mAh g^(−1) at 10.0 large current density and 140.6 mAh g^(−1) at−30℃ as well as the remarkable capacity retention of 93.1%after 300 cycles.Meanwhile,the pouch full batteries obtained by 2 wt%Li_(2)MnO_(3) coated Li(Ni_(0.90)Co_(0.05)Mn_(0.05))_(0.98)Ta_(0.02)O_(2) also showed the more stable storage capability,cyclic property in comparison with bare LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2).
基金supported by the National Natural Science Foundation of China (51904340)the Natural Science Foundation of Hunan (2021JJ2020066)+1 种基金the National Key Research and Development Program (2019YFC1907801, 2019YFC1907803 and 2019YFC1907804)the Central South University Innovation-Driven Research Programme (2023CXQD009)。
文摘氟是废旧锂电池回收难以回避的典型杂质元素,其迁移转化行为复杂,制约了高品质正极材料的可控再生制备.本研究通过揭示废旧锂电池在热解、浸出及高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料再生过程中氟的迁移转化规律,为氟的定向调控及材料的可控再生制备奠定理论基础实验结果表明:热解过程中部分氟(45.71%)以气态热解产物的形式释放到大气中,而另一部分氟(52.34%)则向废三元材料的晶格内发生迁移,并随着湿法浸出溶解到镍钴锰的浸出液中.浸出液中少量的氟会在共沉淀制备前驱体过程中迁移到Ni_(0.9)Co_(0.05)Mn_(0.05)(OH)2前驱体材料,并随着配锂烧结掺杂到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料表面.进一步通过调控氟含量发现,当浸出液中氟浓度控制在0.30 g L^(-1)时,引入到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料中的氟不仅不会引起不利相变,而且能够稳定材料结构,从而有效提升再生高镍材料的循环稳定性(1 C电流密度下循环100圈的容量保持率高达95.7%).因此,本研究不仅揭示了废旧锂电池回收过程中氟的迁移转化行为,而且可控再生制备了高性能氟掺杂高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)正极材料,为废旧锂离子电池回收过程中氟的调控提供了理论依据.
基金the financial support from the National Natural Science Foundation of China(Nos.52034011 and 52204328)the Science and Technology Innovation Program of Hunan Province(2023RC305)the Changsha Municipal Natural Science Foundation(kq2202085)。
文摘The poor electrochemical performance of all-solid-state batteries(ASSBs),which is assemblied by Ni-rich cathode and poly(ethylene oxide)(PEO)-based electrolytes,can be attributed to unstable cathodic interface and poor crystal structure stability of Ni-rich cathode.Several coating strategies are previously employed to enhance the stability of the cathodic interface and crystal structure for Ni-rich cathode.However,these methods can hardly achieve simplicity and high efficiency simultaneously.In this work,polyacrylic acid(PAA)replaced traditional PVDF as a binder for cathode,which can achieve a uniform PAA-Li(LixPAA(0<x≤1))coating layer on the surface of single-crystal LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)due to H^(+)/Li^(+)exchange reaction during the initial charging-discharging process.The formation of PAA-Li coating layer on cathode can promote interfacial Li^(+)transport and enhance the stability of the cathodic interface.Furthermore,the partially-protonated surface of SC-NCM83 casued by H^(+)/Li^(+)exchange reaction can restrict Ni ions transport to enhance the crystal structure stability.The proposed SC-NCM83-PAA exhibits superior cycling performance with a retention of 92%compared with that(57.3%)of SC-NCM83-polyvinylidene difluoride(PVDF)after 200 cycles.This work provides a practical strategy to construct high-performance cathodes for ASSBs.
