The Role of Hydrothermal Carbonization in Sustainable Sodium‐Ion Battery Anodes

Abstract

Sodium‐ion batteries as a prospective alternative to lithium‐ion batteries are facing the challenge of developing high‐performance, low‐cost and sustainable anode materials. Hard carbons are appropriate to store sodium ions, but major energy and environmental concerns during their fabrication process (i.e., high‐temperature carbonization) have not been properly assessed. Furthermore, the rational design of high‐performing hard carbon anodes is usually limited by the conventional direct carbonization of organic precursors. Here, the hydrothermal carbonization process is employed as a versatile pre‐treatment method of renewable precursors, followed by high‐temperature carbonization, for producing advanced hard carbon anodes. The critical role of hydrothermal pre‐treatment in regulating the structure for an optimized performance of hard carbon anodes is elucidated, while revealing the sodium‐ion storage mechanism using electrochemical kinetic calculations, advanced characterization and multi‐scale modeling. Furthermore, the environmental impacts of hydrothermal pre‐treatment and subsequent carbonization are evaluated using life cycle assessment compared to direct carbonization. By comparing hard carbon anodes with and without the hydrothermal pre‐treatment, it is verified that the additional hydrothermal process is responsible for enhanced electrochemical performance, increased carbon yields and reduced carbon emissions. The work provides a systematic understanding of functions and energy consumptions of hydrothermal systems to achieve next‐generation sustainable sodium‐ion batteries.

Nitrogen‐Doped Hollow Carbon Spheres Based on Schiff Base Reaction as an Anode Material for High‐Performance Lithium and Sodium Ion Batteries

“…Figure 3a presents the X‐ray diffraction (XRD) patterns of the PTA‐NHCS‐600, PTA‐NHCS‐700, and PTA‐NHCS‐800. Two wide peaks appeared at 23 and 43°, corresponding to the plane expansion of the (002) and (100) crystal planes, and the deformation and dislocation of the internal lattice of carbon [27] . It can be seen that the peak value of (002) moves to the right with an increase in carbonization temperature, implying an increase in the graphitization content, in agreement with the results observed by HRTEM.…”

“…Two wide peaks appeared at 23 and 43°, corresponding to the plane expansion of the (002) and (100) crystal planes, and the deformation and dislocation of the internal lattice of carbon. [27] It can be seen that the peak value of (002) moves to the right with an increase in carbonization temperature, implying an increase in the graphitization content, in agreement with the results observed by HRTEM. The results demonstrated that the spacing of the crystal plane gradually decreases.…”

Biomass-Derived Hard Carbon with Interlayer Spacing Optimization toward Ultrastable Na-Ion Storage

“…Hard carbons prepared through heat treatment of various biomass materials (e.g., sugar cane, lignin, rice husk, and cellulose) , have been investigated extensively considering the wide sources, unique microstructures, and cost-effective traits of those precursors. Further improvement of the sodium storage performance for those biomass-derived hard carbons can also be achieved by regulating the microstructures or electronic properties via heteroatomic doping, − pretreatment, − or postactivation process. , For example, Wan et al . prepared the N/S dual-doped porous hard-carbon with high performance by pyrolysis of the biomass waste (medicine residue), followed by sequential KOH activation, vacuum drying, mixture with melamine and thioacetamide for N/S doping, and final annealing treatment.…”

Toward Emerging Sodium‐Based Energy Storage Technologies: From Performance to Sustainability

“…[37] Through the theoretical calculation from the life cycle perspective, the CO 2 emissions of each stage within the fabrication of sodium-based energy storage devices from material preparation to cell assembly can be estimated, which can provide a reference for the comparison to current commercial lithium-ion batteries. [38] Except for CO 2 emissions, the life cycle assessment can tell the possibility of land acidification, water pollution and many other environmental issues during the whole fabrication process. Also, based on the difference in raw material and power suppliers, the life cycle assessment can exhibit the environmental effects of the fabrication process on different countries and areas.…”