Activated Carbon from Spartina alterniflora and Its N-Doped Material for Li-Ion Battery Anode

The rampant growth of Spartina alterniflora has been wreaking havoc on the coastal ecosystems, leading to a serious environmental challenge in recent years. One potential solution to this issue involves converting Spartina alterniflora into activated carbon, offering a potential remedy for pollution while creating value in energy storage applications. Herein, through a facile carbonization process with sodium hydroxide activation, we successfully transformed obsolete Spartina alterniflora into a porous carbon material (called SAC) and its nitrogen-doped derivative (denoted as SANC) by using melamine as the nitrogen source in a similar procedure. The amorphous structure of these materials was confirmed to enhance lithium-ion storage and electrolyte permeation, making them ideal for use as anodes in lithium-ion batteries. As a result, both SAC and SANC, derived from Spartina alterniflora, exhibited outstanding electrochemical performance including high capacity (456.7 and 780.8 mA h g^-1 for SAC and SANC, respectively, at the current density of 6 mA g^-1), excellent rate performance (from 6 to 600 mA g^-1) and long-term cycling stability. Notably, compared to SAC, its N-doped derivative SANC showed superior properties in the battery (retaining a reversible capacity of 412.9 mA h g^-1 at the current density of 6 mA g^-1 even after 600 repeated charge-discharge cycles), demonstrating the significantly positive impact of heteroatom doping. This work not only offers a strategy to mitigate environmental challenges but also demonstrates the potential for converting waste biomass into a valuable resource for energy storage applications.