Synthesis and electrochemical characteristics of oligo[{3,4‐diphenyl‐1,1‐di(propan‐2‐yl)‐2,5‐silolene}‐co‐(diphenylsilylene)] for lithium‐ion secondary battery anodes

Abstract

The co-oligomerization of 2,5-dibromo-3,4-diphenyl-1,1-di(propan-2-yl)-silole (3) with dichlorodiphenylsilane was carried out using n-butyllithium at À78 C to synthesize oligo[{3,4-diphenyl-1,1-di(propan-2-yl)-2,5-silolene}-co-(diphenylsilylene)] ( 5) as yellowish-white powder, with a mass-average molar mass of 561, polydispersity of 1.01, λ abs,max of 260 and 279 nm, λ ex,max of 296 nm, λ em,max of 391 nm, and thermal stability up to 125 C without any weight loss. The rate performance obtained with oligomer 5 was superior to that obtained with monomer 3. The discharge and charge capacities with 5 were 1234 and 1263 mAhg À1 , respectively, with Coulombic efficiency of 97.7% at the 100th cycle. Nyquist plots suggested that the resistance decreases gradually with repeated cycling.

Recent progress in Co‐free, Ni‐rich cathode materials for lithium‐ion batteries

“…[1][2][3][4] Lithium-ion batteries (LIBs) are in enormous demand in many applications such as vehicle transportation, stationary energy storage, portable electronics, and large-scale energy systems. [5][6][7][8][9][10][11][12][13][14][15] The attractive applications of LIBs are mainly due to their superior energy density and longer service life, [16][17][18][19][20][21] and these properties are dependent on the electrochemical performance of the cathode electrode material. [22][23][24] The cathode electrode design must account for material cost, safety, and structural stability capabilities, and it can be used to create promising high-performance LIBs.…”

“…The development of eco‐friendly energy storage devices is urgently required due to the continuous depletion of fossil fuels, environmental pressures, and the deepening global economic crisis 1–4 . Lithium‐ion batteries (LIBs) are in enormous demand in many applications such as vehicle transportation, stationary energy storage, portable electronics, and large‐scale energy systems 5–15 . The attractive applications of LIBs are mainly due to their superior energy density and longer service life, 16–21 and these properties are dependent on the electrochemical performance of the cathode electrode material 22–24 .…”