λ-MnO2 as material with pseudocapacitive properties

1. λ-MnO2 as material with pseudocapacitive properties

Pavel Zipunov
Group 413

2. Types of capacitors

3. The crystal structure of spinel and λ-MnO2

4. 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

5. Micrographs of the samples

• (a) LiMn2O4
• (b) λ-MnO2

6. Results

• XRD patterns of LiMn2O4 and λ-MnO2.

7. Results

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

8.

Thank you for attention