micro-nano structure hard carbon as a high performance anode material for sodium-ion batteries - small lithium ion battery
Superior first-
Efficiency of circular Cullen (above 80%)
Display with filter paper-derived micro-
Nano-structured hard carbon, after 100 cycles, it provides a high reversible capacity of 28 6 mah g-1 as Na-
Ion battery of 20 ma g-1.
These superior performance features are attributed to the unique micro
Nano-structure, reducing the first irrevocable loss of capacity by limiting the contact between the electrode and electrolyte, and by accelerating the electron and Na-
Through internal ion transferconnected nano-
Particles and nanoparticles
Pores are respectively.
Good electrical performance indicates this low
Cost hard carbon could be a promising anode for Na-ion batteries.
Filter paper obtained from Special Paper Industry Company (Hangzhou)
Cut into small pieces.
KOH was purchased from Kemiou chemical reagent company (Tianjin)
Use without further purification.
Generally, 3g of the filter paper pioneer body is loaded in a tube furnace for the pyrolysis and carbonizing process (
2 °c/h, heating rate: 5 °c-cmin)
In the atmosphere of ar
Grind the resulting products and wash them with 0.
1 m HCl and deionized water, then collected by filtration.
After drying at 80 °c for 12 h, direct pyrolysis of micro-carbon (DPC)is obtained.
Some DPC samples are dispersed in 7 m KOH aqueous solution and stirred for 2 hours (
The mass ratio of KOH: C is 20:1)
Then, the static soak is carried out for another 24 hours under the environmental conditions.
Filter the mixture by filter paper to remove the additional KOH solution and then dry the mixture for 12 hours at 110 °c.
In an oxygen atmosphere, KOH activates the solid mixture for 2 hours at 800 °c.
After cooling, the mixture is repeatedly used de-
Until the ionization water with a pH value of 7.
The sample is then dried for 12 hours at 65 °c.
Finally, the filter paper-derived micro-
Carbon nanoparticles were obtained, expressed as DPC-A.
Synthesis process of-
DPC is the same ~
A, except for the starting material.
Original filter paper with starting material-
DPC, although for DPC-A. X-
X-ray powder diffraction (XRD)
The mode is to purchase Rigaku D/MAX2200PC tik diffraction and Cu (λu2009=u20091. 54178u2009Å)
Radiation working at room temperature.
The Raman spectrum was collected on the InVia co-focal Raman microscope system and at room temperature, the Taoyuan nm line of the helium ion laser was used as the excitation source. X-
Optoelectronic spectrum (XPS)
Make measurements on X
Ray photoelectric spectrometer (ESCALab MKII).
Infrared spectrum (
KBr particle technique, 0.
1% sample: KBr mass ratio)
Recorded on a Perkin-Elmer Fourier transform instrument with an average of 4 cm scans at a nominal resolution of 100 to improve the signal-to-noise ratio.
Scanning electron microscopy using field emission (FE-
(Japanese Tian Wen S4800)and high-
Resolution transmission electron microscopy (
JEOL 2100F).
Pore size distribution is calculated from the adsorption branch of N adsorption thermodynamics using the Bruna-emit-Taylor surface area analyzer (
Of course, Mike ASAP2020, USA).
For electrode preparation, hard carbon derived (80u2009wt%)Carbon Black (10u2009wt%, Super-P)
, Polyfluoride (PVDF)binder (10u2009wt%)in N-methyl-2-
It's good and bad.
Paste the obtained uniform paste on the copper foil, and then dry in a vacuum oven at 110 ° c for 12 ° h.
Electrochemical test battery (2032 coin battery)
Assembled in an ar-
Fill the glove box (Ou2009≤u20090.
1 u2009 ppm HO u2009 ≤ u2009 3 u2009 ppm)
Copper foil covered with active material as working electrode, Na metal foil as counter/reference electrode, and 1 m solution of NaClO, use a 1:1 vol volume/volume mixture of ethylene carbonate/propylene carbonate as an electrolyte. Glass fiber (Whatman)
Used as a separator.
The battery charges and discharges in a current manner in a fixed voltage window between 0. 01u2009V to 3.
0 v on the Neware battery tester (SHENZHEN, China)
At room temperature
Cyclic KVA (CV)
Performed at room temperature on an electrolytic Workstation (CHI 660E).