λ-MnO2 as material with pseudocapacitive properties презентация

Types of capacitors

The crystal structure of spinel and
λ-MnO2

Experimental reactions
1) synthesis of LiMn2O4
2Li2CO3 + 8MnO2 → + 4LiMn2O4 + 2CO2 + O2
2) synthesis of λ-MnO2
2LiMn2O4 + H2SO4→4λ−MnO2+ Li2SO4 + H2
3) Pseudocapacitive reaction on the surface of electrode
Li2+ + 2λ−MnO2 + e− ⇌ LiMn2O4

Micrographs of the samples
(a) LiMn2O4
(b) λ-MnO2

Results
XRD patterns of LiMn2O4 and λ-MnO2.

Results
CV curves of the samples at a scan rate of 1 mV/s: (a) AC (b) λ-MnO2.