Improvement of cycling stability of Li _{1. 2} Mn _{0 . 54} Co _{0 . 13} Ni _{0 . 13}

Abstract

Summary A thin polyaniline layer that was covered on the surface of the microrod‐like lithium‐rich Mn‐based oxide (LMO, Li1.2Mn0.54Co0.13Ni0.13O2) was formed by in‐situ polymerization of the aniline monomer in HCl or (CF3SO2)2NH (HTFSI) aqueous solution. The results of morphology analysis and structural characterization show that the uniform polyaniline coating layer has a thickness of 6 to 8 nm and the polymerization process does not spoil the integrity of the LMO microstructure. Electrochemical impedance spectroscopy and constant charge/discharge measurement show that polyaniline coating can significantly decrease the interfacial charge transfer resistance, and improve cyclic stability by reducing electrolyte corrosion. Cycling at the current density of 0.1 A g−1 for 100 cycles, the polyaniline‐coated LMO synthesized in HTFSI acidic media exhibits the discharge capacity of 212.2 mAh g−1and high stability (91.98% retention of initial capacity). The high performance is a result of the activation of LMO in HTFSI acidic solution and the role of the (CF3SO2)2N− counterions in the polyaniline chains.

An All-Climate Nonaqueous Hydrogen Gas–Proton Battery

“…Figure a shows the nuclear magnetic resonance (NMR) results of the various electrolytes. It is found that with the increase of H + concentration, the 1 H NMR signal gradually shifted upfield (toward lower ppm values), indicating that the solvation around H + is enhanced. , Meanwhile, as can be seen from the characterization results of Fourier transform infrared spectroscopy (FT-IR) in Figure b, the wavelength of the characteristic groups corresponding to S–N (∼795 cm –1 ), N–H (∼1353 cm –1 ), and SO (∼1473 cm –1 ) shifted to higher wavenumbers with the increase of H + concentration, namely a “blue shift”. ,, The results showed that the interaction between the anion and H + was enhanced in high-concentration electrolytes, which was also consistent with the 1 H NMR characterization results.…”

“…37,38 Meanwhile, as can be seen from the characterization results of Fourier transform infrared spectroscopy (FT-IR) in Figure 1b, the wavelength of the characteristic groups corresponding to S−N (∼795 cm −1 ), N−H (∼1353 cm −1 ), and S�O (∼1473 cm −1 ) shifted to higher wavenumbers with the increase of H + concentration, namely a "blue shift". 37,39,40 The results showed that the interaction between the anion and H + was enhanced in high-concentration electrolytes, which was also consistent with the 1 H NMR characterization results.…”