Limits...
Self-assembly formation of hollow Ni-Fe-O nanocage architectures by metal-organic frameworks with high-performance lithium storage.

Guo H, Li T, Chen W, Liu L, Qiao J, Zhang J - Sci Rep (2015)

Bottom Line: The stable cyclic performance is obtained for all rates from 1 C to 10 C.Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1).Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry Science and Engineering, Yunnan University, Kunming 650091,Yunnan, China.

ABSTRACT
A hollow hybrid Ni-Fe-O nanomaterial (NiFe2O4) is synthesized using a precursor of metal-organic frameworks through a simple and cost-effective method. The unique hollow nanocage structures shorten the length of Li-ion diffusion. The hollow structure offers a sufficient void space, which sufficiently alleviates the mechanical stress caused by volume change. Besides, the hybrid elements allow the volume change to take place in a stepwise manner during electrochemical cycle. And thus, the hierarchical hollow NiFe2O4 nanocage electrode exhibits extraordinary electrochemical performance. The stable cyclic performance is obtained for all rates from 1 C to 10 C. Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1). Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles. This strategy that derived from NMOFs may shed light on a new route for large-scale synthesis of hollow porous hybrid nanocages for energy storage, environmental remediation and other novel applications.

No MeSH data available.


Electrochemical performance of prepared hierarchical porous hollow NiFe2O4 nanocage electrode: (a) cycling performance of CoFe2O4 materials at different temperatures from 200 °C to 400 °C at constant current density of 1 C; (b) the cycle of CV curve with a scan rate of 0.05 mVs−1; (c) charge/discharge curves of CoFe2O4 (350 °C) electrode for the 1st, 2nd, and 200th cycle at current density of 1 C; (c) the first cycle CV curve with a scan rate of 0.05 mVs−1; (d) rate capability of NiFe2O4 electrode from 1 C to 20 C for 200 cycles. Electrode potential range of 0.01–3.0 V vs. Li/Li+.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4562299&req=5

f7: Electrochemical performance of prepared hierarchical porous hollow NiFe2O4 nanocage electrode: (a) cycling performance of CoFe2O4 materials at different temperatures from 200 °C to 400 °C at constant current density of 1 C; (b) the cycle of CV curve with a scan rate of 0.05 mVs−1; (c) charge/discharge curves of CoFe2O4 (350 °C) electrode for the 1st, 2nd, and 200th cycle at current density of 1 C; (c) the first cycle CV curve with a scan rate of 0.05 mVs−1; (d) rate capability of NiFe2O4 electrode from 1 C to 20 C for 200 cycles. Electrode potential range of 0.01–3.0 V vs. Li/Li+.

Mentions: The electrochemical performance of the prepared hollow NiFe2O4 nanocages as anode material of Li-ion batteries was also tested. As shown in Fig. 7a, the increase in cycling stability and capacity with increasing temperature from 200 °C to 400 °C is mainly attributed to the formation of hollow porous structure. The capacity of the sample at 350 °C remains a stable value as high as 1071 mAhg−1 after 200 cycles. However, its capacity fades drastically from 1242 to 552 mAh g−1 after 200 cycles when the temperature is increased to 400 °C, which is caused by the collapse of hollow structure in the process of calcination at high temperature as evidenced in Fig. 6. The CV and charge/discharge curves of hierarchical hollow NiFe2O4 nanocage (350 °C) electrode are shown in Fig. 7b,c, respectively. In the first scan of CV, two cathodic peaks can be observed at 0.54 and 1.51 V, corresponding to the conversion reactions of Fe3+ and Ni2+ to their metallic states and the formation of Li2O30. The broad anodic peaks can be ascribed to the oxidation reactions of metallic Fe and Ni. The reactions of NiFe2O4 with Li can be written as Equations (2) and (3)31:


Self-assembly formation of hollow Ni-Fe-O nanocage architectures by metal-organic frameworks with high-performance lithium storage.

Guo H, Li T, Chen W, Liu L, Qiao J, Zhang J - Sci Rep (2015)

Electrochemical performance of prepared hierarchical porous hollow NiFe2O4 nanocage electrode: (a) cycling performance of CoFe2O4 materials at different temperatures from 200 °C to 400 °C at constant current density of 1 C; (b) the cycle of CV curve with a scan rate of 0.05 mVs−1; (c) charge/discharge curves of CoFe2O4 (350 °C) electrode for the 1st, 2nd, and 200th cycle at current density of 1 C; (c) the first cycle CV curve with a scan rate of 0.05 mVs−1; (d) rate capability of NiFe2O4 electrode from 1 C to 20 C for 200 cycles. Electrode potential range of 0.01–3.0 V vs. Li/Li+.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562299&req=5

f7: Electrochemical performance of prepared hierarchical porous hollow NiFe2O4 nanocage electrode: (a) cycling performance of CoFe2O4 materials at different temperatures from 200 °C to 400 °C at constant current density of 1 C; (b) the cycle of CV curve with a scan rate of 0.05 mVs−1; (c) charge/discharge curves of CoFe2O4 (350 °C) electrode for the 1st, 2nd, and 200th cycle at current density of 1 C; (c) the first cycle CV curve with a scan rate of 0.05 mVs−1; (d) rate capability of NiFe2O4 electrode from 1 C to 20 C for 200 cycles. Electrode potential range of 0.01–3.0 V vs. Li/Li+.
Mentions: The electrochemical performance of the prepared hollow NiFe2O4 nanocages as anode material of Li-ion batteries was also tested. As shown in Fig. 7a, the increase in cycling stability and capacity with increasing temperature from 200 °C to 400 °C is mainly attributed to the formation of hollow porous structure. The capacity of the sample at 350 °C remains a stable value as high as 1071 mAhg−1 after 200 cycles. However, its capacity fades drastically from 1242 to 552 mAh g−1 after 200 cycles when the temperature is increased to 400 °C, which is caused by the collapse of hollow structure in the process of calcination at high temperature as evidenced in Fig. 6. The CV and charge/discharge curves of hierarchical hollow NiFe2O4 nanocage (350 °C) electrode are shown in Fig. 7b,c, respectively. In the first scan of CV, two cathodic peaks can be observed at 0.54 and 1.51 V, corresponding to the conversion reactions of Fe3+ and Ni2+ to their metallic states and the formation of Li2O30. The broad anodic peaks can be ascribed to the oxidation reactions of metallic Fe and Ni. The reactions of NiFe2O4 with Li can be written as Equations (2) and (3)31:

Bottom Line: The stable cyclic performance is obtained for all rates from 1 C to 10 C.Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1).Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry Science and Engineering, Yunnan University, Kunming 650091,Yunnan, China.

ABSTRACT
A hollow hybrid Ni-Fe-O nanomaterial (NiFe2O4) is synthesized using a precursor of metal-organic frameworks through a simple and cost-effective method. The unique hollow nanocage structures shorten the length of Li-ion diffusion. The hollow structure offers a sufficient void space, which sufficiently alleviates the mechanical stress caused by volume change. Besides, the hybrid elements allow the volume change to take place in a stepwise manner during electrochemical cycle. And thus, the hierarchical hollow NiFe2O4 nanocage electrode exhibits extraordinary electrochemical performance. The stable cyclic performance is obtained for all rates from 1 C to 10 C. Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1). Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles. This strategy that derived from NMOFs may shed light on a new route for large-scale synthesis of hollow porous hybrid nanocages for energy storage, environmental remediation and other novel applications.

No MeSH data available.