Recent progress on electrolyte additives for stable lithium metal anode

It has been a long-term challenge to improve the phase stability of Ni-rich LiNixMnyCo1-x-yO2 (x ≥ 0.6) transition metal (TM) oxides for large-scale applications. Herein, a new structure engineering strategy is utilized to optimize the structural arrangement of Li1+x(Ni0.88Mn0.06Co0.06)1-xO2 (NMC88) with a different Li-excess content. It was found that structure stability and particle sizes can be tuned with suitable Li-excess contents. NMC88 with an actual Li-excess of 2.7% (x = 0.027, Li/TM = 1.055) exhibits a high discharge capacity (209.1 mAh g-1 at 3.0-4.3 V, 0.1 C) and maintains 91.7% after the 100th cycle at 1 C compared with the NMC88 sample free of Li-excess. It also performs a delayed voltage decay and a good rate capacity, delivering 145.8 mAh g-1 at a high rate of 10 C. Multiscale characterization technologies including ex/in situ X-ray diffraction (XRD), focused ion beam (FIB) cutting-scanning electronic microscopy (SEM), and transmission electron microscopy (TEM) results show that a proper Li-excess (2.7%) content contributes to the formation of a broader Li slab, optimized cation mixing ratio, and even particle sizes. Therefore, NMC88 with a proper Li-excess is a good choice for next-generation cathode materials.

Synthesis and Mechanism of High Structural Stability of Nickel-Rich Cathode Materials by Adjusting Li-Excess.

An integrated surface coating strategy to enhance the electrochemical performance of nickel-rich layered cathodes

Recycling of spent lithium-ion batteries in view of green chemistry

In this work, a fast ionic conductor, Li1.3Al0.3Ti1.7(PO4)3 (LATP), has been successfully coated on a Ni-rich LiNi0.8Co0.1Mn0.1O2 surface by an improved sol–gel method with postannealing at 575 °C....

Enhanced electrochemical performance of Ni-rich cathode materials with Li1.3Al0.3Ti1.7(PO4)3 coating

One-step recovery of valuable metals from spent Lithium-ion batteries and synthesis of persulfate through paired electrolysis

High consumption of acids and reductants is usually required when spent lithium-ion batteries are recycled using a hydrometallurgy route. The overstoichiometric chemicals end up as pollutants that have to be further treated. Low chemical and energy consumption have attracted considerable attention to achieve sustainability of a recycling process. In this research, LiFePO₄ was used as a reductant and induced crystallization was performed for the removal of Fe and P. More importantly, we demonstrate that it is possible to achieve additional reductant-free and near-to-stoichiometric acidic recovery of spent ternary lithium-ion batteries (NCMs) by introducing FePO₄·2H₂O seed crystals and using waste LiFePO₄. High efficiencies (>96%) of critical metals including Ni, Co, Mn, and Li are achieved, while iron phosphate remains as a solid product. Then, the leaching solution can be further used for the Ni–Co–Mn hydroxide precursor and lithium carbonate preparation. In addition, the mechanisms were subsequently investigated by combining thermodynamics analysis and systematic characterizations. This entire recycling process can be a highly economic, closed-loop alternative for recovering valuable metals from spent lithium-ion batteries.

Dingshan Ruan

Papers

Enhanced electrochemical performance of Ni-rich cathode materials with Li1.3Al0.3Ti1.7(PO4)3 coating

One-step recovery of valuable metals from spent Lithium-ion batteries and synthesis of persulfate through paired electrolysis

Near-to-Stoichiometric Acidic Recovery of Spent Lithium-Ion Batteries through Induced Crystallization

Dual-strategy of Cu-doping and O3 biphasic structure enables Fe/Mn-based layered oxide for high-performance sodium-ion batteries cathode