Pathways toward Improved Performance of NCM523 Pouch Cell via Incorporating Low-Cost Al₂O₃ and Graphene

Abstract

Improving the holistic capability for lithium-ion batteries (LIBs) using an efficient and convenient approach with a minimum cost increase remains one of the most urgent and challenging issues for LIB industrialization. This work delivers such an approach via an extremely simple path. Low-cost reagents of Al 2 O 3 and graphene sheets (Gs) are used as additives for LiNi 05 Co 0.2 Mn 0.3 O 2 (NCM523)∥graphite pouch cells. Interestingly, with very low concentrations (only 1.0 and 0.5 wt % for Al 2 O 3 and graphene), additives enable dramatically improved LIB performance, from cyclic stability, energy density, to thermal safety. The assembled cell of NCM523-Al 2 O 3 -Gs∥graphite delivered a capacity retention of 76.9% at 3.0 C after 400 cycles (cf. only 73.6% for a pure NCM cell). More significantly, the heat generation during the discharging under 3.0 C and safety tests are both superior to those of a pure NCM cell. It is proven that the excellent LIB performance benefits from the coeffect of additives of Al 2 O 3 and Gs, which not only inhibit the structure failure and enhance conductance of materials but also optimize the interface compatibility of an electrolyte and slow down the thermal runaway possibility, especially at high rates and elevated temperatures. This work provides a powerful and convenient solution for the commercial achievement of high-performance LIBs.

Growth of Polyhedral LiNi0.5Co0.2Mn0.3O2 Crystals in a Molten Li3BO3 Flux and Their Role in Electrode Density and Dispersion Design

“…With the addition of 20 wt % NCM523-970, the dispersibility of NCM523 is improved, increasing the electrode density (Figure e,f). The filling rate of our designed two-particle mixture electrode is superior to that of an electrode made of amorphous submicron particles as the filler . Due to the synergetic contributions of this dispersion and the isotropic shape characteristic of NCM523-970, the two-particle mixture electrode exhibits high filling efficiency and low electrode resistance.…”

“…The filling rate of our designed twoparticle mixture electrode is superior to that of an electrode made of amorphous submicron particles as the filler. 31 Due to the synergetic contributions of this dispersion and the isotropic shape characteristic of NCM523-970, the two-particle mixture electrode exhibits high filling efficiency and low electrode resistance. Notably, the conduction efficiency of the NCM523-970@20 wt % two-particle mixture electrode is similar to that of the single-particle NCM523-970 electrode, despite the presence of only a small quantity of crystalline NCM523 particles.…”

Novel n–i CeO2/a-Al2O3 Heterostructure Electrolyte Derived from the Insulator a-Al2O3 for Fuel Cells

“…This proves that CeO 2 and a-Al 2 O 3 formed the interfacial contact network. 29,30 Subsequently, the energy-dispersive X-ray spectroscopic (EDS) mapping of the main elements of the heterostructure composite are shown in Figure 2d−f, in which the Al, Ce, and O elements are homogeneously distributed throughout the entire region, and a small proportion of a-Al 2 O 3 is surrounded by CeO 2 . The results indicate that the insulator−semiconductor heterostructure interface is built.…”

“…As an insulation material with an ultrawide band gap, Al 2 O 3 has the advantages of low price and abundant resources, and it has high mechanical strength, good dielectric properties, high-temperature insulation resistance, chemical corrosion resistance, and good thermal conductivity, which can improve the cycle stability, energy density, and thermal safety of electrochemical devices. ,, Following the above-mentioned properties of the insulator, and considering the properties of amorphous alumina (a-Al 2 O 3 ), in this study, an n–i heterostructure electrolyte is developed using CeO 2 as an n-type semiconductor and a-Al 2 O 3 as the insulator, and its performance and the enhancing mechanism derived from the insulator a-Al 2 O 3 are investigated in LT-SOFCs. The developed heterostructure composite electrolyte exhibited enhanced ionic conductivity and fuel cell performance at 400–550 °C.…”

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

“…Inspiringly, previous studies have shown that a trace of Al doping can stabilize the layered structure and improve the cycling stability of NCM cathode materials. − We thus anticipate that the utilization of the aforementioned “Al impurity” to repair elemental vacancies in NCM lattices during direct recycling can simplify the purification process as well as enhance the electrochemical performance of recycled materials. Furthermore, the Al compensation for Ni, Co, and Mn elemental losses in NCM structures is expected to be helpful in improving the stability of layered structure in normal recycling processes, leading to additional advantages on the electrochemical performance of the recycled NCM material.…”