Journal of Materials Science, Vol.56, No.1, 649-663, 2021
Optimized pseudocapacitance of CoMn2O4@MoO(3)nano-microspheres for advanced lithium storage properties
This manuscript introduces the ball-milling and subsequent heat treatment to gain CoMn2O4@MoO(3)nano-microsphere composite with optimized pseudocapacitance behavior. The prepared ternary composite material forms the stable core-shell structure as well as realizes fined nanoparticles of the microsphere surface from the slowly thermal decomposition of molybdate. The CoMn2O4@MoO(3)hybrid as electrode of the half-cell showing high capacity 1410 mA h g(-1)at 0.5 A g(-1)after 500 cycles and excellent rate capability (1028 mA h g(-1)at 2 A g(-1)). The experiment results further confirm thatbvalues of CoMn2O4@MoO3(i = a v(b), scan ratevand currenti) are over 0.9 in LIBs, indicating an obvious pseudo-capacitive process. Insights into the pathways of this pseudo-capacitive process indicate that Faradaic pseudocapacitance and strong interactions at the two-phase interface of the composite electrode, contributing to optimized electronic environment for enhancing the charge-transfer kinetics and energetics and Li(+)storage. Additionally, the core-shell structure relieves volume expansion of nano-microspheres from ion intercalation, benefiting to improve stable cycle. Advanced specific surface area would benefit the penetrated electrolyte with nano-microspheres and expedite electrons/ions transformation, effectively reducing concentration polarization in anode electrode. Specially, the full cell including anode CoMn2O4@MoO(3)and cathode LiFePO(4)also own excellent electrochemical performance, reflecting the practical application value of the hybrid material for lithium ion battery.