All-solid-state lithium batteries(ASSLBs)are important for enhancing safety across various applications related to lithium-ion batteries(LIBs).Lithium iron phosphate(LiFePO4)is a widely utilized commercial cathode in ...All-solid-state lithium batteries(ASSLBs)are important for enhancing safety across various applications related to lithium-ion batteries(LIBs).Lithium iron phosphate(LiFePO4)is a widely utilized commercial cathode in LIBs,prized for its stable cycling performance,thermal stability,and low cost.However,low electronic conductivity and slow ion diffusion kinetics limit its application at high rates and low temper-atures.Herein,Ti3C2Tx MXene nanosheets(NSs)are introduced into the LiFePO4 cathode.The continu-ous electron-conducting networks are constructed due to the high electrical conductivity of Ti3C2Tx NSs.Meanwhile,the coordination environment of lithium ions in the cathode is weakened by the oxygenated end groups of Ti3C2Tx NSs,and thus efficient ion-percolating networks are constructed.Therefore,the ionic and electronic conductivities of the modified cathode are significantly improved.Assembled all-solid-state LiFePO4/Li full cells with poly(ethylene oxide)as electrolyte exhibits high initial discharged capacities of 91.5 mAh g^(-1) at 10 C,and capacities of 155.1 mAh g^(-1) after 1000 cycles at 1 C with a re-tention rate of 93.8%.Furthermore,the cells still deliver excellent performance at high loading,room temperature,and low temperature.This work offers a facile and scalable strategy for designing high-performance ASSLBs.展开更多
Cathode material LiFePO4 of lithium-ion battery was synthesized by microwave heating. The "carbon-included" LiFePO4 with improved conductivity was synthesized by the addition of graphite. And the influence o...Cathode material LiFePO4 of lithium-ion battery was synthesized by microwave heating. The "carbon-included" LiFePO4 with improved conductivity was synthesized by the addition of graphite. And the influence of microwave-heating time on structure, morphology and charge/discharge performance of the products was discussed. The results of XRD, SEM, XPS, CV and charge/discharge testing measurements showed that the LiFePO4 product after 9 min in microwave oven had more advantages than other products.展开更多
Besides Li＋ and Mg2＋, the electrochemical behavior of Na^＋ and K＋ in LiFePO4/FePO4 structures was studied since they naturally coexist with Li＋ and Mg2＋ in brine. The cyclic voltammogram （CV） results indicated...Besides Li＋ and Mg2＋, the electrochemical behavior of Na^＋ and K＋ in LiFePO4/FePO4 structures was studied since they naturally coexist with Li＋ and Mg2＋ in brine. The cyclic voltammogram （CV） results indicated that Na＋ exhibits some reversibility in LiFePO4/FePO4 structures. Its reduction peak appears at -0.511 V, more negative than that of Li＋ （-0.197 V）, meaning that a relatively positive potential is beneficial for decreasing Na＋ insertion. The reduction peak of K＋ could not be found clearly, indicating that K＋ is difficult to insert into the FePO4 structure. Furthermore, technical experiments using real brine with a super high Mg/Li ratio （493） at a cell voltage of 0.7V showed that the final extracted capacity of Li＋, Mg2＋ and Na＋ that can be attained in 1 g LiFePO4 is 24.1 mg, 7.32 mg and 4.61 mg, respectively. The Mg/Li ratio can be reduced to 0.30 from 493, and the Na/Li ratio to 0.19 from 16.7, which proves that, even in super high Mg/Li ratio brine, if a cell voltage is appropriately controlled, it is possible to separate Li^＋ and other impurities effectively.展开更多
采用氧化物前驱体对磷酸铁锂(LiFePO4)进行少量金属离子掺杂,并用XRD ,SEM 和恒电流充放电对掺杂的LiFePO4 进行了研究。结果表明,少量的掺杂离子在很大程度上提高了LiFePO4 的电化学性能,特别是大电流放电性能。1.0 m ol% 的Nb5+掺杂Li...采用氧化物前驱体对磷酸铁锂(LiFePO4)进行少量金属离子掺杂,并用XRD ,SEM 和恒电流充放电对掺杂的LiFePO4 进行了研究。结果表明,少量的掺杂离子在很大程度上提高了LiFePO4 的电化学性能,特别是大电流放电性能。1.0 m ol% 的Nb5+掺杂LiFePO4 的0.1 C 放电容量约150 m Ah·g-1;即使在3 C 倍率下放电,也有117 m Ah·g-1 的容量。掺杂的效果与掺杂离子的半径、价态密切相关,半径小、价态高的离子对提高LiFePO4 的电化学性能有利。在掺杂量较小时(<2.0 m ol% ),掺杂效果与掺杂离子的浓度关系不大。展开更多
Pure olive-type phased LiFePO4 powders were successfully synthesized b y hydrothermal processes. The samples were investigated by X-ray diffraction, sc anning electron microscopy and so on. Results showed that hydroth...Pure olive-type phased LiFePO4 powders were successfully synthesized b y hydrothermal processes. The samples were investigated by X-ray diffraction, sc anning electron microscopy and so on. Results showed that hydrothermal product w ere of pure olive-type phase with a relatively smaller particle size and regular er morphology compared with the products prepared by solid-state reaction and ba ll milling activation approaches. Charge/discharge curves at 0.5 C rate revealed that the hydrothermal products had a first discharge capacity of 124 mAh·g-1, and the capacity fading rate was only 10.7% after 50 cycles.展开更多
基金supported by the Natural Science Foundation of Shandong Province(Nos.ZR2022QE014 and ZR2021QH237)the National Natural Science Foundation of China(Grant Nos.52401221,51971120,and U1902221)the Medical StaffScience and Technology Plan of Shandong Province(No.SDYWZGKCJH2022073).
文摘All-solid-state lithium batteries(ASSLBs)are important for enhancing safety across various applications related to lithium-ion batteries(LIBs).Lithium iron phosphate(LiFePO4)is a widely utilized commercial cathode in LIBs,prized for its stable cycling performance,thermal stability,and low cost.However,low electronic conductivity and slow ion diffusion kinetics limit its application at high rates and low temper-atures.Herein,Ti3C2Tx MXene nanosheets(NSs)are introduced into the LiFePO4 cathode.The continu-ous electron-conducting networks are constructed due to the high electrical conductivity of Ti3C2Tx NSs.Meanwhile,the coordination environment of lithium ions in the cathode is weakened by the oxygenated end groups of Ti3C2Tx NSs,and thus efficient ion-percolating networks are constructed.Therefore,the ionic and electronic conductivities of the modified cathode are significantly improved.Assembled all-solid-state LiFePO4/Li full cells with poly(ethylene oxide)as electrolyte exhibits high initial discharged capacities of 91.5 mAh g^(-1) at 10 C,and capacities of 155.1 mAh g^(-1) after 1000 cycles at 1 C with a re-tention rate of 93.8%.Furthermore,the cells still deliver excellent performance at high loading,room temperature,and low temperature.This work offers a facile and scalable strategy for designing high-performance ASSLBs.
文摘Cathode material LiFePO4 of lithium-ion battery was synthesized by microwave heating. The "carbon-included" LiFePO4 with improved conductivity was synthesized by the addition of graphite. And the influence of microwave-heating time on structure, morphology and charge/discharge performance of the products was discussed. The results of XRD, SEM, XPS, CV and charge/discharge testing measurements showed that the LiFePO4 product after 9 min in microwave oven had more advantages than other products.
基金Project(K1205034-11) supported by Technology Program of Changsha,China
文摘Besides Li＋ and Mg2＋, the electrochemical behavior of Na^＋ and K＋ in LiFePO4/FePO4 structures was studied since they naturally coexist with Li＋ and Mg2＋ in brine. The cyclic voltammogram （CV） results indicated that Na＋ exhibits some reversibility in LiFePO4/FePO4 structures. Its reduction peak appears at -0.511 V, more negative than that of Li＋ （-0.197 V）, meaning that a relatively positive potential is beneficial for decreasing Na＋ insertion. The reduction peak of K＋ could not be found clearly, indicating that K＋ is difficult to insert into the FePO4 structure. Furthermore, technical experiments using real brine with a super high Mg/Li ratio （493） at a cell voltage of 0.7V showed that the final extracted capacity of Li＋, Mg2＋ and Na＋ that can be attained in 1 g LiFePO4 is 24.1 mg, 7.32 mg and 4.61 mg, respectively. The Mg/Li ratio can be reduced to 0.30 from 493, and the Na/Li ratio to 0.19 from 16.7, which proves that, even in super high Mg/Li ratio brine, if a cell voltage is appropriately controlled, it is possible to separate Li^＋ and other impurities effectively.
文摘采用氧化物前驱体对磷酸铁锂(LiFePO4)进行少量金属离子掺杂,并用XRD ,SEM 和恒电流充放电对掺杂的LiFePO4 进行了研究。结果表明,少量的掺杂离子在很大程度上提高了LiFePO4 的电化学性能,特别是大电流放电性能。1.0 m ol% 的Nb5+掺杂LiFePO4 的0.1 C 放电容量约150 m Ah·g-1;即使在3 C 倍率下放电,也有117 m Ah·g-1 的容量。掺杂的效果与掺杂离子的半径、价态密切相关,半径小、价态高的离子对提高LiFePO4 的电化学性能有利。在掺杂量较小时(<2.0 m ol% ),掺杂效果与掺杂离子的浓度关系不大。
文摘Pure olive-type phased LiFePO4 powders were successfully synthesized b y hydrothermal processes. The samples were investigated by X-ray diffraction, sc anning electron microscopy and so on. Results showed that hydrothermal product w ere of pure olive-type phase with a relatively smaller particle size and regular er morphology compared with the products prepared by solid-state reaction and ba ll milling activation approaches. Charge/discharge curves at 0.5 C rate revealed that the hydrothermal products had a first discharge capacity of 124 mAh·g-1, and the capacity fading rate was only 10.7% after 50 cycles.
