Electrochemical Properties of the LiNi_0.6Co_0.2Mn_0.2O₂ Cathode Material Modified by Lithium Tungstate under High Voltage

Abstract

An amount (5 wt %) of lithium tungstate (LiWO) as an additive significantly improves the cycle and rate performances of the LiNiCoMnO electrode at the cutoff voltage of 4.6 V. The 5 wt % LiWO-mixed LiNiCoMnO electrode delivers a reversible capacity of 199.2 mA h g and keeps 73.1% capacity for 200 cycles at 1 C. It retains 67.4% capacity after 200 cycles at 2 C and delivers a discharge capacity of 167.3 mA h g at 10 C, while those of the pristine electrode are only 44.7% and 87.5 mA h g, respectively. It is shown that the structure of the LiNiCoMnO cathode material is not affected by mixing LiWO. The introduced LiWO effectively restrains the LiPF and carbonate solvent decomposition by consuming PF at high cutoff voltage, forming a stable cathode/electrolyte interface film with low resistance.

Boosting the cycling stability of Ni-rich layered oxide cathode by dry coating of ultrastable Li3V2(PO4)3 nanoparticles

“…To investigate the electrode reaction process, CV profiles of the two electrodes were compared at different cycles under 0.1 mV s −1 between 3.0-4.3 V. A pair of oxidation and reduction peaks at about 3.6-3.9 V can be found in all CV curves for the NCM622 electrode, indicating the Ni 2+ /Ni 4+ transformation of NCM622. 35 The current density became lower with the increase of cycle numbers due to the reduced electrochemical capacity (Fig. 3e).…”

Isocyanoethyl Methacrylate (IMA) as a Bifunctional Electrolyte Additive for LiNi0.8Co0.1Mn0.1O2/Graphite Batteries with Enhanced Performance

“…Figure 5 shows the C 1s, O 1s, F 1s and N 1s XPS spectra of NCM811 cathode in different electrolytes after 450 cycles at room temperature and normal voltage. In the C 1s spectrums of NCM811 cathode surface (Figure 5a), [27,41–45] the main peak at 284.7 eV is attributed to C−C and C−H in conductive carbon black and PVDF binder, while C−F in PVDF is at 290.7 eV. The C−O and C=O from the decomposition products of the electrolyte is located at 286.1 and 289.2 eV, respectively.…”

The effect of chelating agent on synthesis and electrochemical properties of LiNi0.6Co0.2Mn0.2O2

“…The more nickel content, the higher discharge capacity, however, it also leads to the structural instability of the cathode materials, the serious Li/Ni ion mixing and the poor cycling performance, and so on [10][11][12]. In order to integrate the high capacity, long cycle life and low cost of LiNi 1−x−y Co x Mn y O 2 composite oxide, many papers have focused on LiNi 0.6 Co 0.2 Mn 0.2 O 2 composite oxide [13][14][15][16].…”