Epitaxial Regeneration of Spent Graphite Anode Material by an Eco-friendly In-Depth Purification Route

Abstract

Recovery of spent graphite (SG) anode has been largely overlooked and undervalued due to the difficult regeneration process and the relative low price of graphite compared to valuable elements in the cathode. Moreover, lacking feasible low-cost techniques for the recovery of SG seriously restricts the development of all-component recycling of end-of-life batteries. Here, a novel in-depth purification process via KOH–NaOH composite alkali etching is proposed to eliminate impurities incorporated in SG. Residual acid-insoluble impurities, such as Al- and Fe-related compounds, can be removed effectively by alkali roasting treatment at 180–300 °C. Furthermore, in situ TEM investigation is conducted to unravel the gradual graphitization of the coating layer and the construction of Li+ transport channels between the newly formed structures and the original graphite bulk particles via an epitaxial growth manner during the regeneration process. After optimized purification and regeneration treatments, the recycled graphite can be used suitably as a regenerated anode, and a full cell containing commercial LiFePO4 and recycled graphite shows satisfactory capacity retention of 85.8% after 500 cycles at 1 C. This work demonstrates a promising recyclization route of SG anodes.

Ultra‐fast, low‐cost, and green regeneration of graphite anode using flash joule heating method

“…We list comparison to other similar recent work which was shown in Table S2. [32][33][34][35][36][37][38] Compared with other processes, the graphite anode recovered by our method shows higher ICE, almost full recovery of capacity, very low cost, and short time consumption. This method is a cost-effective reported method for anode regeneration.…”

Regeneration of anode materials from complex graphite residue in spent lithium-ion battery recycling process

“…2a). 19,24,25 The organic matter content was roughly obtained based on the mass difference before and after calcination at 500 °C for 2 h. It was demonstrated that the graphite residue contained about 11.9 wt% of organic matter.…”

“…This implies that there is a certain increase in purity, a certain degree of crystal shape recovery, and an extension of the graphite layer after dehybridization. 19,20 Fig. 6b shows the Raman spectrum of GR before and after impurity removal.…”

Aluminum Impurity from Current Collectors Reactivates Degraded NCM Cathode Materials toward Superior Electrochemical Performance

“…T he fast expanding of electric vehicles (EVs) and hybrid electric vehicles (HEVs) in the state-of-the-art automotive market is increasing the demand for high-performance power batteries, 1 among which the ternary NCM (LiNi 0.5 Co 0.2 Mn 0.3 O 2 ) materials have almost achieved their dominance as the preferred cathode materials because of their moderate price and high capacity. 2,3 Consequently, a problem arises: the disposal of scrapped ternary power batteries from EVs and HEVs has gradually become an environmental challenge and a social issue.…”