Preventing Structural Collapse and Thermal Runaway to Improve the Electrochemical Performance and Safety of LiNi_0.8Co_0.1Mn_0.1O₂ by a Negative-Thermal-Expansion Material of Al₂(WO₃)₄

Abstract

Nickel-rich layered oxides such as LiNi0.8Co0.1Mn0.1O2 (NCM811) deliver high specific capacity and attract extensive interest for applications, but they still face some challenges of capacity fade and thermal runaway. Herein, NCM811 was modified with a cheap orthorhombic negative-thermal-expansion (NTE) material of Al2(WO3)4 to improve its electrochemical performance and safety by adjusting the heat, deformation, and interface via a simple strategy. The NCM811 material modified with 7 wt % Al2(WO3)4 (NA7) exhibits excellent electrochemical performance, thermal stability, and safety. Its reversible capacities can retain 162.0 and 171.5 mA h g–1 after 100 cycles at 25 and 60 °C, respectively, about 13.8 and 25.4% higher than those of the pristine NCM811. Simultaneously, the strain value after cycles and released heat from differential scanning calorimetry of NCM811 are decreased by Al2(WO3)4 about 50.6 and 45.3%, respectively. With the modification of Al2(WO3)4, the exothermic peak of NCM811 is up-shifted from 206.1 to 223.8 °C, while the side reaction, morphology breakdown, and structural damage are significantly prevented. According to multifarious results using various techniques, the enhancement mechanism of Al2(WO3)4 for NCM811 is proposed. It supplies a facile strategy to improve the performance and safety of energy materials using a cheap NTE material.

Challenges and opportunities using Ni-rich layered oxide cathodes in Li-ion rechargeable batteries: the case of nickel cobalt manganese oxides

“…177 The addition of a negative-thermal-expansion (NTE) material of Al 2 (WO 3 ) 4 leads to improvement in the thermal stability. 178 The formation of the rock-salt layer on the surface of NCM811 is reported to enhance the thermal stability of an NCM cathode with high Ni contents. 179 The change in the total heat generation with degradation suggests a strong correlation between the heat generation and crystal structure changes during cycling, as indicated by differential scanning calorimetry (DSC) measurements and XAS measurements.…”

High-Performance High-Nickel Multi-Element Cathode Materials for Lithium-Ion Batteries

“…The surface coating of high-nickel cathode materials mainly includes metal oxides, metal fluorides, metal phosphates, lithium-containing compounds, and non-metallic compounds. Metal oxide surface coatings mainly include SiO 2 [158][159][160], ZrO 2 [161], TiO 2 [162][163][164], Al 2 O 3 [165], Ta 2 O 5 [166], Al+Ti [167], Al+W [168], Co+Ti [169], Co+B [170], Co+Al [171], La+Ca [172], etc. Sun et al [163] prepared spherical high-nickel cathode material LiNi 0.9 Co 0.08 Al 0.02 O 2 with 0.4 wt% TiO 2 coating using the immersion-hydrolysis method.…”

“…Structural analysis showed that NCA-Ta 2 O 5 maintained a good spherical structure without obvious cracks after 200 cycles at 1 C, while the original NCA experienced severe structural collapse. Wang and colleagues [167] synthesized NCM811 with Al and W coatings. The coated NCM811 exhibited excellent electrochemical stability and safety, and the capacity retention rates after 100 cycles at 25 • C and 60 • C were improved by 13.8% and 25.4%, respectively.…”

The Modification of WO3 for Lithium Batteries with Nickel-Rich Ternary Cathode Materials

“…From the local amplification of the (003) diffraction peak, compared to the original sample, the (003) peak of the SC-NCM622-1.0% WO 3 sample shifted significantly towards a lower angle, indicating an increase in the c-axis of the sample. The increased interlayer spacing was significantly beneficial for lithium electron transport during the charging and discharging of the lithium battery [30]. The lattice parameters of the ratio of all samples I (003)/I (104) are shown in Table 3.…”