Enhanced Electrochemical Properties of LiNi_0.8Co_0.1Mn_0.1O₂ at Elevated Temperature by Simultaneous Structure and Interface Regulating

Abstract

Inferior cycling stability at elevated temperature is a big challenge for the commercial application of nickel-rich cathode materials because more serious phase transition, transition metal ion dissolution and side reaction of interface happen at elevated temperature than at room temperature. In the present work, strategies of element doping and surface coating are utilized together to stabilize the structure and interface electrochemistry. We successfully synthesized a Zr-doped and LiAlO 2 -Al 2 O 3 coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 material by a simple ball milling and wet chemical method. Owing to the synergistic effect of Zr doping and dual LiAlO 2 -Al 2 O 3 coating, when cycled at 50°C, the modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 sample exhibited significantly improved cycling stability with a capacity retention of over 96.8% after 60 cycles at a current rate of 1C, while the pristine sample could only retain a capacity of 73.3%. This improved electrochemical performance can be attributed to the effective doping and coating technique employed to the LiNi 0.8 Co 0.1 Mn 0.1 O 2 sample. The Zr doping is beneficial to reduce cation mixing and suppress the phase transition, while the LiAlO 2 -Al 2 O 3 coating helps to enhance the protection of the electrode/electrolyte interface and reduce the transition metal ion dissolution.

A Comprehensive Analysis of the Interphasial and Structural Evolution over Long‐Term Cycling of Ultrahigh‐Nickel Cathodes in Lithium‐Ion Batteries

“…This conclusion is further confirmed by the distribution behavior of NiF 2 − (fluorinated transition‐metal fragment), 6 Li 2 F + (originates from the reaction between F‐containing species such as PF 6 − , POF 3 , and HF with the rest of 6 Li in the charged cathode), and C 2 HO − (stems from electrolyte decomposition) . It is interesting to note that the signals of NiF 2 − are weaker toward the edge of the particle, which indicates the transition‐metal ions on the cathode surface are dissolved upon contact with HF and diffuse to the electrolyte …”

“…[35][36][37] At charged state, the reaction between electrolyte and cathode is significantly deteriorated. [39][40][41] As a result, the intrinsic correlation between lattice distortion and cathode surface reaction in ultrahigh-Ni layered oxides is revealed. Given 7 Li + only comes from the electrolyte, it is a strong evidence that electrolyte continually diffuses into the secondary particle and reacts with the cathode.…”

A Three in One Strategy to Achieve Zirconium Doping, Boron Doping, and Interfacial Coating for Stable LiNi0.8Co0.1Mn0.1O2 Cathode

“…Materials Preparation: Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursor was synthesized via a co-precipitation method which had been reported in the pre-vious work. [43] The Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursor, ZrB 2 nanoparticles (provided by Beijing Deke Daojin Science and Technology Co., Ltd.), and LiOH•H 2 O with Li:TM:ZrB 2 ratio of 1.05:1:0.001 were thoroughly mixed by ball milling. Excess lithium (0.05 mol%) was added to compensate the lithium loss when sintering at high temperature.…”

An Integrated Device of a Lithium-Ion Battery Combined with Silicon Solar Cells

“…As shown in Table 1, the values of c/a and I 003 /I 104 were larger than 4.9 and 1.2, respectively. Thus, the sample had a well-ordered layered structure and a lower amount of Li + /Ni 2+ mixing [20]. The refined atomic parameters of Ni, Co, and Mn were 0.65, 0.15, and 0.20, respectively, as shown in Table 2.…”