Preparation and properties of Ni-Fe oxide : carbon composites
Wei, Guanghao (2021)
Wei, Guanghao
2021
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2021072216831
https://urn.fi/URN:NBN:fi:amk-2021072216831
Tiivistelmä
In this essay, Ni(NO3)2·6H2O, Fe(NO3)3·9H2O are firstly chosen as nickel and iron source, and glycerol and isopropanol are used as organic solvents to make them react in the solution. After this, NiFe-glyceric acid precursor is obtained. Calcine the precursor and the NiFe2O4 nanosphere is got. Next, take water as the solvent to prepare a solution, add graphene oxide aqueous dispersion as well. And finally NiFe2O4/rGO hydrogel is obtained by hydrothermal method. Use water to wash away the impurities, then freeze-drying, and finally NiFe2O4/rGO aerogel is obtained.
The material characterization analysis and electrochemical performance analysis are carried out. The successful combination of NiFe2O4 and rGO has been proved by operating TEM, FESEM, XRD and Ramen analysis on it. It is found that NiFe2O4 nanospheres are embedded onto the ‘net’ of rGO and at the same time NiFe2O4/rGO aerogel composite material has already been 3D structured. Also it is found that there are a large number of pores in the aerogel, which promote the transfer of charges inside the batteries under the synergy effect of NiFe2O4 and rGO.
Besides, NiFe2O4/rGO aerogel is taken to operate electrochemical analysis as electrode materials of LIBs to see its ability as future sustainable energy. First its initial discharge capacity is up to 1654mA h g-1. Besides, NiFe2O4/rGO aerogel also shows a stable rate performance and long cycling stability, even under high current density(1000 mA g-1) and 200 cycles, the capacity of the aerogel still remained about 482 mA h g-1 finally. The above results finally illustrate that NiFe2O4/rGO composite has a superior electrocheimcal performance. And it proved that the combination of NiFe2O4 and rGO can perfectly make up for the shortcomings of low cycle capacity and serious capacity reduction when NiFe2O4 is used as an electrode material alone and the shortcomings of low theoretical specific capacity when rGO is used as an electrode material alone.
The material characterization analysis and electrochemical performance analysis are carried out. The successful combination of NiFe2O4 and rGO has been proved by operating TEM, FESEM, XRD and Ramen analysis on it. It is found that NiFe2O4 nanospheres are embedded onto the ‘net’ of rGO and at the same time NiFe2O4/rGO aerogel composite material has already been 3D structured. Also it is found that there are a large number of pores in the aerogel, which promote the transfer of charges inside the batteries under the synergy effect of NiFe2O4 and rGO.
Besides, NiFe2O4/rGO aerogel is taken to operate electrochemical analysis as electrode materials of LIBs to see its ability as future sustainable energy. First its initial discharge capacity is up to 1654mA h g-1. Besides, NiFe2O4/rGO aerogel also shows a stable rate performance and long cycling stability, even under high current density(1000 mA g-1) and 200 cycles, the capacity of the aerogel still remained about 482 mA h g-1 finally. The above results finally illustrate that NiFe2O4/rGO composite has a superior electrocheimcal performance. And it proved that the combination of NiFe2O4 and rGO can perfectly make up for the shortcomings of low cycle capacity and serious capacity reduction when NiFe2O4 is used as an electrode material alone and the shortcomings of low theoretical specific capacity when rGO is used as an electrode material alone.