Construction of Planar Gliding Restriction Buffer and Kinetic Self-Accelerator Stabilizing Single-Crystalline LiNi_0.9Co_0.05Mn_0.05O₂ Cathode

Abstract

The single-crystalline Ni-rich cathode has aroused much attention for extenuating the cycling and safety crises in comparison to the polycrystalline cathode. However, planar gliding and kinetic hindrance hinder its chemo-mechanical properties with cycling, which induce delamination cracking and damage the mechanical integrity in single crystals. Herein, a robust Li2.64(Sc0.9Ti0.1)2(PO4)3 (LSTP) ion/electron conductive network was constructed to decorate single-crystal LiNi0.9Co0.05Mn0.05O2 (SC90) particles. Via physicochemical characterizations and theoretical calculations, this LSTP coating that evenly grows on the SC90 particle with good lattice matching and strong bonding effectively restricts the anisotropic lattice collapse along the c-axis and the cation mixing activity of SC90, thus suppressing planar gliding and delamination cracking during repeated high-voltage lithiation/delithiation processes. Moreover, such a 3D LSTP network can also facilitate the lithium-ion transport and prevent the electrolyte’s corrosion, lightening the kinetic hindrance and triggering the surface phase transformation. Combined with the Li metal anode, the LSTP-modified SC90 cell exhibits a desirable capacity retention of 90.5% at 5 C after 300 cycles and stabilizes the operation at 4.3/4.5 V. Our results provide surface modification engineering to mitigate planar gliding and kinetic hindrance of the single-crystalline ultra-high Ni-rich cathode, which inspires peers to design other layered cathode materials.

In Situ Constructing Ultrastable Mechanical Integrity of Single‐Crystalline LiNi0.9Co0.05Mn0.05O2 Cathode by Interior and Exterior Decoration Strategy

“…Materials Preparation: The precursor Ni 0.9 Co 0.05 Mn 0.05 (OH) 2 composite powder is exactly synthesized by a coprecipitation process, which is reported in previous work. [38] To obtain single-crystalline LiNi 0.9 Co 0.05 Mn 0.05 O 2 (SC90, abbreviated as SC SC90), the precursor Ni 0.9 Co 0.05 Mn 0.05 (OH) 2 was thoroughly mixed with LiOH•H 2 O (the molar ratio of Li:Me = 1.05:1) and then calcined at 830 °C for 10 h in an oxygen atmosphere. After the high-temperature solid-state calcination reaction, the obtained powder sample was crushed to yield dense micrometersized individual single-crystal particles.…”

Advancements in Addressing Microcrack Formation in Ni–Rich Layered Oxide Cathodes for Lithium–Ion Batteries

“…Surface coating is another promising strategy to maintain a stable material by inhibiting or weakening detrimental side reactions between the cathode and electrolyte [2f,18] . The ideal coating layer should not only prevent the cathode's surface from electrolyte corrosion but also guarantee smooth Li‐ion transport and electronic contact.…”

Regulating the Charge Distribution of Oxygen by High-Entropy Doping to Stabilize Single-Crystal Ni-Rich Cathode Materials

“…With the increasing demand for high-energy-density lithium-ion batteries (LIBs) in electric vehicles and consumer electronics, Li(Ni 1– x –y Co x Mn y )O 2 , a ternary layered oxide cathode material, is the most promising cathode material due to its high theoretical capacity, high operating voltage, and low production cost. − Compared with polycrystalline ternary cathode materials, the single crystallization of a nickel-rich cathode material not only avoids the problems of intergranular cracks faced by polycrystalline particles due to the elimination of a large number of grain boundaries and pores between secondary particles inside the material but also suppresses the side reaction between the nickel-rich cathode and the electrolyte to a certain extent, enhancing the cycling stability and the safety of the battery. − It can further enhance the tap density of the material and thus improve the energy density of the cathode . The specific capacity of the material is improved with the increase of nickel content, especially the nickel-rich (Ni ≥ 0.8) cathode materials that have a specific capacity of nearly 200 mAh/g.…”

“…4−6 It can further enhance the tap density of the material and thus improve the energy density of the cathode. 7 The specific capacity of the material is improved with the increase of nickel content, especially the nickel-rich (Ni ≥ 0.8) cathode materials that have a specific capacity of nearly 200 mAh/g. However, the high nickel content easily triggers poor cycling stability and thermal stability, hindering the practical application of nickel-rich cathode materials.…”