High‐Voltage‐driven Li/Mn‐rich Li_1.2Mn_0.6Ni_0.1Co_0.1O₂ Cathode with nanocomposite blend gel polymer electrolyte for long cyclic stability of rechargeable Li‐battery

Abstract

Li/Mn‐rich layered oxide is an attractive cathode material for Li‐ion battery due to its low cost, high specific capacity, and high working potential. In this paper, the high capacity layered Li/Mn‐rich NMC cathode (Li1.2Mn0.6Ni0.1Co0.1O2) and nanocomposite blend gel polymer electrolytes (NBGPEs) are synthesized by using the sol‐gel method and solution casting technique, respectively. XRD results confirm that the cathode material has a well‐defined hexagonal layered structure. It is observed that the synthesized NBGPE containing 2 wt.% SiO2 nanofiller exhibits maximum ionic conductivity (5.2 mS cm−1), Li‐ion conductivity (~2.40 mS cm−1), and wide electrochemical stability (~5.4 V vs Li/Li+) at 30°C. The electrochemical performance of the cell (Li/NBGPE#1/Li1.2Mn0.6Ni0.1Co0.1O2) has been investigated by cyclic voltammetry and galvanostatic charge–discharge measurement. The cell delivers maximum specific discharge capacity of 212.0 mAh g−1 at 0.1C and good rate performance within 2.0‐4.8 V. At 0.2C, the cell shows stable coulombic efficiency ~98% after 200th cycle due to better interfacial stability between NBGPE#1 and the electrode.

Jointly Improving Anionic–Cationic Redox Reversibility of Lithium-Rich Manganese-Based Cathode Materials by N Surface Doping

“…It is further proven that N exists on the surface of LNMO-N in the form of Li–N bonds. The samples exhibit a Lorentzian shape and additional signal at g = 2.003 in the electron paramagnetic resonance (EPR) results (Figure h), supporting the existence of oxygen vacancies in LNMO and LNMO-N. Thermogravimetric analysis (TGA) was employed to determine the mean oxygen vacancy content in the samples . Since the maximum weight percentage of the two samples is approximately 100.18%, as shown in Figure S3, the oxygen vacancy content in LNMO-N and LNMO is calculated to be δ = 0.01.…”

“…XPS and sXAS were employed to investigate the surface chemical state of Ni and Mn in LNMO-N, as shown in Figures i–l. The binding energies of Ni 2p 3/2 in LNMO are measured to be 855.9 and 873.1 eV, indicating the presence of Ni 2+ and Ni 3+ . Moreover, the observed shift toward lower energy for the Ni 2p peaks in LNMO-N suggests a reduction of some Ni 3+ to Ni 2+ .…”