The effects of precipitant agent on structure and performance of LiNi1/3Co1/3Mn1/3O2 cathode material via a carbonate co-precipitation method

A Fast Approach to Obtain Layered Transition-Metal Cathode Material for Rechargeable Batteries

Li-ion batteries as a support for future transportation have the advantages of high storage capacity, a long life cycle, and the fact that they are less dangerous than current battery materials. Li-ion battery components, especially the cathode, are the intercalation places for lithium, which plays an important role in battery performance. This study aims to obtain the LiNixMnyCozO2 (NMC) cathode material using a simple flash coprecipitation method. As precipitation agents and pH regulators, oxalic acid and ammonia are widely available and inexpensive. The composition of the NMC mole ratio was varied, with values of 333, 424, 442, 523, 532, 622, and 811. As a comprehensive study of NMC, lithium transition-metal oxide (LMO, LCO, and LNO) is also provided. The crystal structure, functional groups, morphology, elemental composition and material behavior of the particles were all investigated during the heating process. The galvanostatic charge–discharge analysis was tested with cylindrical cells and using mesocarbon microbeads/graphite as the anode. Cells were tested at 2.7–4.25 V at 0.5 C. Based on the analysis results, NMC with a mole ratio of 622 showed the best characteristicd and electrochemical performance. After 100 cycles, the discharged capacity reaches 153.60 mAh/g with 70.9% capacity retention.

Preparation and electrochemical investigation of single-crystal LiNi0.6Co0.2Mn0.2O2 for high-performance lithium-ion batteries

Ni-rich layered cathode materials have large reversible capacity.

Morphology-Conserved Transformations of Metal-Based Precursors to Hierarchically Porous Micro-/Nanostructures for Electrochemical Energy Conversion and Storage

To meet future market demand, developing new structured materials for electrochemical energy conversion and storage systems is essential. Hierarchically porous micro-/nanostructures are favorable for designing such high-performance materials because of their unique features, including: i) the prevention of nanosized particle agglomeration and minimization of interfacial contact resistance, ii) more active sites and shorter ionic diffusion lengths because of their size compared with their large-size counterparts, iii) convenient electrolyte ingress and accommodation of large volume changes, and iv) enhanced light-scattering capability. Here, hierarchically porous micro-/nanostructures produced by morphology-conserved transformations of metal-based precursors are summarized, and their applications as electrodes and/or catalysts in rechargeable batteries, supercapacitors, and solar cells are discussed. Finally, research and development challenges relating to hierarchically porous micro-/nanostructures that must be overcome to increase their utilization in renewable energy applications are outlined.

Preparation and Rate Capability of Carbon Coated LiNi1/3Co1/3Mn1/3O2 as Cathode Material in Lithium Ion Batteries

LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) is regarded as a promising material for next-generation lithium ion batteries due to the high capacity, but its practical applications are limited by the poor electronic conductivity. Here, a one-step method is used to prepare carbon coated LiNi_1/3Co_1/3Mn_1/3O₂ (NCM/C) by applying active carbon as reaction matrix. TEM shows LiNi_1/3Co_1/3Mn_1/3O₂ particles are homogeneously coated by carbon with a thickness about 10 nm. NCM/C delivers the discharge capacity of 191.2 mAh g^-1 at 0.5 C (85 mA g^-1) with a columbic efficiency of 91.1%. At 40 C (6800 mA g^-1), the discharge capacity of NCM/C is 54.6 mAh g^-1, whereas NCM prepared through sol-gel route only delivers 13.2 mAh g^-1. After 100 charge and discharge cycles at 1 C (170 mA g^-1) the capacity retention is 90.3% for NCM/C, whereas it is only 72.4% for NCM. The superior charge/discharge performance of NCM/C owes much to the carbon coating layer, which is not only helpful to increase the electronic conductivity but also contributive to inhibit the side reactions between LiNi_1/3Co_1/3Mn_1/3O₂ and the liquid electrolyte.