High lithium and sodium anodic performance of nitrogen-rich ordered mesoporous carbon derived from alfalfa leaves by a ball-milling assisted template method

Abstract

Alfalfa leaves rich in crude protein were used as a nitrogen-containing carbon precursor to prepare N-rich ordered mesoporous carbon (OMC) by a ball-milling assisted SBA-15 template method. The obtained alfalfa leaf-derived nitrogen-rich ordered mesoporous carbon (ALNOMC) with a surface area of 727.8 m² g⁻¹, a pore size distribution centering mainly at around 3.8 nm and a N-content of 7.19 wt% offers superb dual functionality as an anode for lithium ion batteries (LIBs) and sodium ion batteries (NIBs). For LIB applications, ALNOMC delivers a superior reversible capacity of 1635 mA h g⁻¹ after 10 cycles at 0.1 A g⁻¹, excellent rate capability of 492 mA h g⁻¹ at 5 A g⁻¹ and cycling stability of 924 mA h g⁻¹ after 400 cycles at 1 A g⁻¹. Tested against Na, ALNOMC offers a high initial reversible capacity of 433 mA h g⁻¹ and stable reversible capacity of 407 mA h g⁻¹ at 0.1 A g⁻¹. The rate and cycling performances are also impressive, being as high as 218 mA h g⁻¹ even after 200 cycles at 1 A g⁻¹.