Researchers found a way to make manganese selenide (MnSe) electrodes where its expansion can be tamed.
In lithium ion (li-ion) batteries, anode and cathode electrodes play a very important role in their performance. Anode plays a critical role as it acts as a host reversibly allowing li-ion intercalation/deintercalation during charge/discharge cycles. Manganese Selenium (MnSe) is a promising candidate as an anode material for lithium ion batteries. But these electrodes swell almost 160% during charging-discharging cycles, breaking apart itself.
To overcome this challenge, the researchers from the Korea Maritime and Ocean University have found a way to embed MnSe in a 3D carbon nanosheet matrix where its expansion can be controlled. The work is described in the Chemical Engineering Journal.
They used a sol-gel and selenation route for making anode. The resulting material has a uniform MnSe nanoparticles anchored in the carbon nanosheet matrix (CNM) and had been named ‘MnSe ⊂ 3DCNM’.
According to the paper, the structure formed has a high surface area and other advantages “leading to full lithiation – delithiation reactions, excellent electrochemical kinetics and buffer volume expansion of MnSe nanoparticles”.
The MnSe based electrode has a stable reversible capacity of 665.5mAh/g after 200 cycles and a sustained coulombic efficiency close to 100%. Moreover, it demonstrated superior performance when combined with a LiMn2O4 cathode in a full battery.
“Using a conducive filler scaffold, we have developed an anode that boosts the battery performance while simultaneously allowing reversible energy storage,” said engineer Jun Kang. “This strategy can serve as a guide for other transition metal selenides with high surface areas and stable nanostructures, with applications in storage systems, electrocatalysis, and semiconductors.”