A Simple Gas–Solid Treatment for Surface Modification of Li‐Rich Oxides Cathodes

Abstract

Li-richl ayered oxides with high capacity are expected to be the next generation of cathode materials. However,t he irreversible and sluggish anionic redox reaction leads to the O 2 loss in the surface as well as the capacity and voltage fading.I nt he present study,asimple gas-solid treatment with ferrous oxalate has been proposed to uniformly coat at hin spinel phase layer with oxygen vacancy and simultaneously realize Fe-ion substitution in the surface.T he integration of oxygen vacancy and spinel phase suppresses irreversible O 2 release,p revents electrolyte corrosion, and promotes Li-ion diffusion. In addition, the surface doping of Fe-ion can further stabilizet he structure.A ccordingly,t he treated Feox-2 %c athode exhibits superior capacity retention of 86.4 %a nd 85.5 %a t1Ca nd 2C to that (75.3 %a nd 75.0 %) of the pristine sample after 300 cycles,r espectively. Then, the voltage fading is significantly suppressed to 0.0011 V per cycle at 2Cespecially.T he encouraging results may play asignificant role in paving the practical application of Li-rich layered oxides cathode.

Constructing a Composite Structure by a Gradient Mg2+ Doping Strategy for High-Performance Sodium-Ion Batteries

“…Sodium-ion batteries (SIBs) have been deemed as an appealing alternative for electrochemical energy storage systems on a large scale by virtue of the analogous working principle with lithium-ion batteries (LIBs), abundant reserves, and attractive cost. − Moreover, cathode materials are of great significance in determining the operating voltage and energy density. − Among many cathode materials, layered transition metal oxides possess high specific capacity, cost effectiveness, and convenience for large-scale preparation. − In particular, P2-type Na 0.67 Mn 0.67 Ni 0.33 O 2 (P2-NMNO) materials are supposed to be an attractive cathode alternative for commercialization due to the high voltage profile (average voltage ≥3.5 V), high specific capacity, and good stability in an ambient atmosphere and moisture. , Nevertheless, bulk failure caused by the high-voltage P2–O2 phase transformation (4.2 V vs Na + /Na) results in large volume expansion and contraction. This not only causes inferior Na + diffusion kinetics but also gives rise to the initiation and propagation of cracks .…”

Synthesis and Application of an Aromatic Sulfonate Sodium Salt for Aqueous Sodium‐Ion Battery Electrolytes

“…Lithium‐ion batteries (LIBs) are one of the major choices for energy storage in modern portable consumer electronics and electric vehicles. [ 1–4 ] However, concerning the enormous consumption and rising price of Li resources, new rechargeable battery systems beyond LIBs have recently drawn a lot of attentions. [ 5–7 ] Thanks to the high abundance of sodium and other raw materials employed, sodium‐ion batteries (SIBs) are expected to offer lower costs than LIBs.…”

Deciphering the degradation discrepancy in Ni‐rich cathodes with a diverse proportion of [003] crystallographic textures

“…In the context of carbon neutrality, new energy sources have developed rapidly, especially lithium batteries, which have been successfully commercialized [1][2][3][4][5] ; here, Ni-rich cathode materials have attracted considerable attention because of their high energy density. [6][7][8][9][10] LiNi 0.8 Co 0.1 Mn 0.1 O 2 and LiNi 0.8 Co 0.15 Al 0.05 O 2 are widely preferred by the market. [11][12][13][14] However, the structural stability is very poor due to the high content of Ni, especially for LiNi x Co y Mn 1−x−y O 2 (x ≥ 0.9).…”