Hydrothermal Synthesis of Tunable Olive‐Like Ni_0.8Co_0.1Mn_0.1CO₃ and its Transformation to LiNi_0.8Co_0.1Mn_0.1O₂ Cathode Materials for Li‐Ion Batteries

Abstract

Uniform olive‐like Ni0.8Co0.1Mn0.1CO3 carbonate precursors were successfully synthesized under hydrothermal conditions. Powder X‐ray diffraction, field emission scanning electron microscopy, optical microscopy, and inductively coupled plasma optical emission spectroscopy revealed that crystal size and elemental contents of carbonate precursors could be slightly tuned by regulating the molar ratio of urea and transition metal ions, moreover, a synergetic crystal evolution mechanism involving Ostwald ripening and crystal etching for the formation of olive‐like carbonate precursors was put forward for the first time. The improvement in temperature facilitated the increment in size of primary particles of oxides transformed from carbonate precursors. Vermiform LiNi0.8Co0.1Mn0.1O2 cathode materials transformed from olive‐like carbonate precursors exhibited high discharge capacity of 193.4 mAh g−1 at 0.2 C, and capacity retention of 85.4 % at 1 C after 100 cycles. Charge transfer impedance (Rct) and diffusion coefficient of lithium ion (DLi+) revealed the electrochemical properties of cathode materials.

Perspective on the Preparation Methods of Single Crystalline High Nickel Oxide Cathode Materials

“…However, the synthesis of precursors offers the opportunity to achieve atomic‐level mixing of TM (transition metal) ions, thereby enhancing reactivity during the subsequent sintering and providing precise control of the final NCM products. Various methods have been explored to synthesize precursors of NCM, including coprecipitation, [ 17,18 ] sol‐gel, [ 19 ] hydrothermal/solvothermal, [ 20,21 ] and spray pyrolysis methods. [ 22 ] Sol‐gel method requires a significant amount of organic chelating agents and results in the generation of waste gas in the subsequent sintering step.…”

Convenient Surface Treatment of LiNi0.8Co0.1Mn0.1O2 Materials Improve the Cycle Performance

“…The research shows that: the closer the ratio c/a is to 4.9, the better the layered performance is. 26 Encouragingly, all the Solvent Treated NCM811 are reduced compared to the Pristine-NCM811, among which the of the Acetonetreated NCM811 is the lowest, 4.9404. Meanwhile, all the Solvent Treated NCM811 increase in volume and decrease in density.…”

Low-cobalt active cathode materials for high-performance lithium-ion batteries: synthesis and performance enhancement methods

“…8a–e show that the morphology of the solvothermal product crucially depends on the reaction time. 66 The yield of the solvothermal product also largely depends on the capacity of the autoclave and bulk production is hard to achieve. The equipment dependency limits its commercial application.…”

“…There are few reports on the solvo/hydrothermal synthesis of low cobalt NCM precursors. [62][63][64][65][66] It is interesting to notice that most of the as-synthesized NCM precursors have a well-dened morphology and the lithiated materials show good electrochemical performance. Fig.…”

“…Hence, other synthesis methods, including hydrothermal, solgel, template assisted synthesis, vapor-phase deposition method, spray pyrolysis, etc., are also explored to produce single crystal Ni-rich NCMs. 66,68,128,[184][185][186][187][188][189] Recently, several efforts have already been made to produce single crystal NCMs with a higher Ni-content and to compare the performance with the polycrystalline one. [190][191][192][193][194][195][196][197][198][199][200][201][202] As an example, Ran et al have shown that single crystal NCM811 is superior in terms of cycling as well as rate performance compared to the polycrystalline one.…”