Enhanced Electrochemical Performance and Thermal Stability of ZrO₂- and rGO–ZrO₂-Coated Li[Ni_0.8Co_0.1Mn_0.1]O₂ Cathode Material for Li-Ion Batteries

Abstract

LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) has been considered as a promising cathode for Li-ion batteries (LIBs) due to its high electrochemical capacity and low cost; however, poor cycling stability is one of the main restricting factors in industrial applications of the NCM811 cathode material. Notably, the capacity fading and low structural stability of NCM811 are intensified at elevated temperatures. ZrO 2 -and composite rGO−ZrO 2 -coated NCM811 were fabricated by a facile wet chemical method and evaluated at 25 and 55 °C to overcome these impediments. The ZrO 2 coating provides superior cycling and thermal stability and perfectly protects the cathode active material from deleterious side reactions, and HF attacks by suppressing the direct contact of NCM811 particles and electrolytes. Despite these advantages, the discharge capacity of the ZrO 2 -coated cathode material (166.3, 187.7 mAh g −1 ) is slightly lower than that of the pristine cathode (171.7, 193.0 mAh g −1 ) due to the insulative nature of ZrO 2 NPs, after one cycle at ambient and elevated temperatures. The first cycle discharge capacity increased to 185.9 and 206.7 mAh g −1 at 25 and 55 °C, respectively, with the rGO−ZrO 2 -coated cathode material. The capacity retention reached 92.4 and 83.3%, showing high capacities of 171.8 and 172.3 mAh g −1 at 1C after 100 cycles at 25 and 55 °C, whereas the pristine cathode material exhibited low retention values of 72.4 and 54.5% with discharge capacities of 124.3 and 105.2 mAh g −1 under the same conditions, respectively. The incorporation of rGO into the coating can make up for the ZrO 2 coating imperfection and, at the same time, can enhance the ion/electron conductivity of the electrode by providing a conductive network on the surface of the cathode material. In light of the fact that ZrO 2 -and composite rGO−ZrO 2 -coated NCM811 cathode materials exhibit superior performance; they can pave the way for industrial applications of high-energy-density lithium-ion batteries. KEYWORDS: LiNi 0.8 Co 0.1 Mn 0.1 O 2 , nanocoating, reduced graphene oxide, ZrO 2 , thermal stability, lithium-ion batteries

Nanometer-thin ZrO2 Coating for NiO on MWCNTs as Anode for Improved Performance of Sodium-Ion Batteries

“…These two bands along with the Raman active bands of NiO remain intact in the nanocomposite sample showing that the structure of MWCNTs and NiO is not damaged during coating, which adds to the electrochemical endurance of the nanocomposite electrode. The presence of ZrO 2 is indicated by the distinctive tiny peak between 150 and 1000 cm –1 . , …”

“…In NiO, NiO-MWCNT, and the ZrO 2 -coated NiO-MWCNT nanocomposite, XPS confirms the impurity-free synthesis and the presence of Ni, C, O, and Zr characteristic peaks. The Ni 2p spectrum contains two component peaks (shown in Figure a): the primary peak positioned at 854.46 eV matches with Ni 2p 3/2 , and the second main peak centered at 872.16 eV corresponds to Ni 2p 1/2 spin–orbit levels of NiO . The peaks that correspond to Ni 2p 3/2 signify the Ni 2+ state.…”

Electrochemical Performance and Elevated Temperature Properties of the TiO2-Coated Li[Ni0.8Co0.1Mn0.1]O2 Cathode Material for High-Safety Li-Ion Batteries

“…Based on Figure , TiO 2 coating acts as a barrier layer to protect the cathode surface from HF attack and microcrack origination and therefore maintains the electrical connection between cathode particles. Also, TiO 2 coating prohibits the interfacial side reactions between the active material and electrolyte and results in a thin SEI layer (higher electrical conductivity and improved lithium-ion diffusion) by minimizing the contact surface between the cathode and electrolyte. ,− As a result, TiO 2 coating enhances the electrochemical performance and safety of the NCM811 cathode material.…”

“…Many researchers have proposed elemental doping, including Al, Mg, Na, and F, and surface modification with WO, SiO 2 , ZrO 2 , , AlF 3 , and Al 2 O 3 coatings to overcome the aforementioned drawbacks of nickel-rich cathode materials. It is believed that the coating strategy is more effective than doping in providing a stable cathode–electrolyte interface and suppressing unwanted side reactions .…”

Visualization of the Final Stage of Sintering in Nanoceramics with Atomic Resolution

“…The choice of ZrO 2 NCs was due to their stability in the face of oxidation state variation and radiation damage, well-known chemical and physical properties, and well-established synthesis and assembly protocols . In addition, ZrO 2 is a widely employed material for different applications, such as catalysts, − composites for light-emitting diodes, , water purification, Li-ion batteries, , and biomedical applications. − We used HRTEM analysis operating at room temperature in free-standing films formed by a monolayer of nanoparticles (without a supporting membrane). By joining the optimized sample preparation, the cleaning protocol, and the constant electron beam illumination, we achieved a sufficient dynamic process, allowing us to visualize the sintering process using a simple single tilt sample holder with very high spatial and temporal resolution.…”