Operando X-ray diffraction analysis of the degradation mechanisms of a spinel LiMn2O4 cathode in different voltage windows

Boosting the Electrochemical Performance of a Spinel Cathode with the In Situ Transformed Allogenic Li-Rich Layered Phase

“…The particle size of primary particles increases with the increase in the amount of lithium-rich phase transformation, but the size of secondary particles does not increase significantly. The surface morphology of S-L-0.4 and S-L-0.5 samples changes significantly, which is similar to the morphology of primary particles on the surface of lithium-rich materials synthesized by the co-precipitate method reported in the previous literature, indicating that the spinel phase changes into the layered phase. − …”

“…The discharge plateau around 2.1 V gradually disappears as the cycle goes on, which may be caused by the spinel sample's irreversible phase transition from the cubic to tetragonal phase due to the Jahn−Teller effect. 39 Figure 5c'−e' shows the dQ/dV curves corresponding to the 2nd, 10th, 20th, and 30th cycles of spinel samples prepared at different sintering temperatures. Li + insertion/extraction is accompanied by the redox of transition metal ions in the voltage range of 3.5−4.95 V. The peaks in the 4.5 -4.8 V voltage range correspond to Ni 2+ /Ni 4+ , and the peaks around 4 V correspond to Mn 3+ /Mn 4+ .…”

“…As shown in Figure c–e, there is an obvious charging plateau at 3.0 V during the cycle of the spinel sample, which is caused by Li + extraction of the 16c octahedral site. The discharge plateau around 2.1 V gradually disappears as the cycle goes on, which may be caused by the spinel sample’s irreversible phase transition from the cubic to tetragonal phase due to the Jahn–Teller effect Figure c’–e’ shows the d Q /d V curves corresponding to the 2nd, 10th, 20th, and 30th cycles of spinel samples prepared at different sintering temperatures.…”

Nano-structured silicon and silicon based composites as anode materials for lithium ion batteries: recent progress and perspectives

“…There have been various studies on the main components of LIBs such as the anode and electrolyte. 5,9,[11][12][13][14] Electrode materials such as Li metal oxides (LiCoO 2 , 15 LiMn 2 O 4 , 16 and LiNiO 2 (ref. 17)) and Li metal phosphates (LiFePO 4 ) 18 are among the widely used cathode materials.…”

Advancement of technology towards high-performance non-aqueous aluminum-ion batteries

“…Lithium-ion batteries (LIBs) have been considered as one of the most major choices for the growing large-scale energy storage system and portable electronic devices, electric automobile in the past decades [6][7][8][9][10]. Nowadays, the commercial positive electrode materials are principally composed of layered LiMn 1ÀxÀy Co x Ni y O 2 [11,12], spinel LiMn 2 O 4 [13,14] or olivine LiFePO 4 [15,16], and the commercial negative electrode materials are mainly carbonbased materials [17][18][19]. The potential of carbon-based anode is very close to that of Li, and the metal Li often separates out on the surface of carbon when the battery is overcharged.…”