Abstract
In past decades, environmental concerns and fossil fuel depletion have spurred the development of green and renewable technologies that can efficiently convert and store energy sources. In particular, lithium-ion batteries (LIBs) have been gaining increasing attention due to their high reversible capacity, outstanding rate performance and cycling stability as well as portability and low pollution. However, the commercially available LIBs with graphite anode cannot meet the ever-increasing demand for high energy density devices, therefore, the exploring of an alternative anode is essential to enhance the energy storage capacity of LIBs. Recently, biomass-derived carbon materials have shown excellent electrochemical performance as a negative electrode, making them an ideal candidate as a new host material for lithium ions.
Here we propose a one-pot, low-cost, and environmentally friendly synthesis method of a bio-derived porous carbon with a high surface area as an anode electrode for LIBs. Four chemical activators such as H2SO4, H3PO4, KOH, and ZnCl2 have been investigated as a facilitator to the formation of the porous structure of activated carbon (AC) from the agar precursor. Among the used chemical activators, AC prepared with the addition of KOH demonstrated the best electrochemical performance in a reaction with lithium metal. The initial discharge capacity reached 931 mAh g-1 and a reversible capacity of 320 mAh g-1 was maintained over 100 cycles at 0.1C. The high rate performance up to 10 C demonstrated stable cycling performance of AC from agar.
Keywords: activated carbon; agar; anode; lithium-ion battery, chemical activators.
Acknowledgments:
This work was supported by the project 091019CRP2114 "Three-Dimensional All Solid State Rechargeable Batteries" from Nazarbayev University.
Graphical abstract
Disordered carbonaceous materials synthesized from an environmentally sustainable agar precursor and their electrochemical characteristics as the anode for LIBs.
Figure 1