A Novel and Sustainable Approach to Enhance the Li-Ion Storage Capability of Recycled Graphite Anode from Spent Lithium-Ion Batteries

Abstract

The ubiquitous manufacturing of lithium-ion batteries (LIBs) due to high consumer demand produces inevitable e-waste that imposes severe environmental and resource sustainability challenges. In this work, the charge storage capability and Li-ion kinetics of the recovered water-leached graphite (WG) anode from spent LIBs are enhanced by using an optimized amount of recycled graphene nanoflakes (GNFs) as an additive. The WG@GNF anode exhibits an initial discharge capacity of 400 mAh g–1 at 0.5C with 88.5% capacity retention over 300 cycles. Besides, it delivers an average discharge capacity of 320 mAh g-1 at 500 mA g–1 over 1000 cycles, which is 1.5–2 times higher than that of WG. The sharp increase in electrochemical performance is due to the synergistic effects of Li-ion intercalation into the graphite layers and Li-ion adsorption into the surface functionalities of GNF. Density functional theory calculations reveal the role of functionalization behind the superior voltage profile of WG@GNF. Besides, the unique morphology of spherical graphite particles trapping into graphene nanoflakes provides mechanical stability over long-term cycling. This work explains an efficient strategy to upgrade the electrochemical compatibility of recovered graphite anode from spent LIBs toward next-generation high-energy-density LIBs.

Stress-Relief Engineering in a N-Doped C-Modified Hierarchical Nanoporous Si Anode with a Microcurved Pore Wall Structure for Enhanced Lithium Storage

“…After recorrosion, the characteristic peaks of the MgO and Mg 2 Si phases disappeared from the spectrum. The diffraction peaks at 2θ = 28.44°, 47.28°, 56.13°, 69.18°, 76.39°, and 88.03° correspond to the (111), (220), (311), (400), (331), and (422) crystal planes of the Si phase (PDF#75-0589), respectively. ,,, The diffraction peak corresponding to the (222) crystal plane at 2θ = 58.85° is not very prominent in the curve due to its relatively low peak intensity. At this stage, the main component of this product has been transformed into Si and the phase structure of the final product remains stable (Figure b).…”

“…1−4 However, with the advancements in portable electronic devices and the growth of the new energy sector, the theoretical specific capacity of the commercially available graphite anode falls short of meeting the increasing market demand. 5,6 Therefore, it is imperative to seek out new anode materials with a higher energy density.…”

“…Lithium-ion batteries (LIBs) have found extensive use in the areas of electronic information and energy storage, owing to their high energy density, long service life, minimal memory effect, and low environmental impact. − However, with the advancements in portable electronic devices and the growth of the new energy sector, the theoretical specific capacity of the commercially available graphite anode falls short of meeting the increasing market demand. , Therefore, it is imperative to seek out new anode materials with a higher energy density.…”

“…Silicon (Si) is considered a promising candidate for anodes in lithium-ion batteries due to its high theoretical specific capacity (3579 mAh g –1 ) at room temperature and abundant natural resources . However, Si anodes undergo a significant volume change (∼300%) during the lithiation/delithiation process, − leading to internal stress and various problems with active substance falling off the collector, instability of the solid electrolyte interface (SEI) layer, failure of the electrical connection between the active substance and the collector, and a decrease in battery capacity, conductivity, and cycle life. − To address these issues, many excellent studies have been reported, including the preparation of Si nanoparticles, , nanorods, nanowires, and nanotubes, the development of active-inertia systems, and the construction of porous structures. ,− Among these, reducing the particle size can stabilize the performance of Si anodes, but significant internal stress accumulates during multiple charges and discharges, eventually leading to battery failure. In contrast, the construction of porous structures can better stabilize the performance of Si anodes. − For example, Sohn et al prepared nonporous and porous micrometer-sized Si/C composite anodes by ball milling and alkaline etching .…”

A review on green and sustainable carbon anodes for lithium ion batteries: utilization of green carbon resources and recycling waste graphite

“…This strategy can realize a high purity of 99.55% for obtained graphite, which exhibits a high specific capacity of 286 mA h g −1 . Bhar et al 176 enhanced the recovered water-leached graphite anode from the spent LIBs using optimized ratio regenerated graphene nanoflake. The recovered-water-leached graphite was prepared to recycle graphene using Hummers’ method and then amalgamated with a regenerated graphite matrix at an opportune ratio.…”