Boron Doping and LiBO₂ Coating Synergistically Enhance the High-Rate Performance of LiNi_0.6Co_0.1Mn_0.3O₂ Cathode Materials

Abstract

The nickel-rich cathode LiNi0.6Co0.1Mn0.3O2 (NCM613) is a promising cathode material but has poor cycle stability, especially at a high cutoff voltage. Aiming at modulating the unit cell parameters via heteroatom dopants while providing a lithium-ion conductor coating, in this work, boron-based-modified NCM613 has been synthesized with both LiBO2 coating and boron doping via a solid-state method. The optimal modified sample LBO-0.4 exhibits excellent cycle stability at room temperature (2.8–4.5 V) with a retention of 94.8% at 1 C after 100 cycles (versus 79.7% of the pristine sample LBO-0) and 70.7% at 5 C after 1000 cycles (versus a retention lower than 1% for LBO-0). The D Li + values of LBO-0.4 are significantly higher than those of LBO-0, which is attributed to the enlarged crystal lattice volume generated by the incorporation of B3+ into NCM613. Combined with characterization by Ar sputtering-assisted XPS, TEM, XRD, etc., it is illustrated that LiBO2 coating and B3+ doping can synergistically enhance the electrochemical performance of the NCM613 at a high cutoff voltage, high temperature, and high rate. In addition, DFT calculations disclose that the boron dopant is preferential to locate in the interstice among three Ni atoms of the TM–O layer of NCM, which facilitates the formation of more amount Ni2+, leading to the improved electrochemical performance of NCM613. Such ion doping and surface coating strategy can provide useful guidance on the modification of other layered oxide cathode materials.

Coordination Anchoring Effect Promoting the Interfacial Stability and Electrochemical Performance of LiNi0.8Co0.1Mn0.1O2 Cathode Material for Lithium‐Ion Batteries

“…Compared with NCM, the lattice oxygen content of P2‐NCM was significantly increased, indicating that the dissolution of transition metal ions was effectively inhibited. [ 5,43 ] In addition, the lower content of CO 2‐ 3 further demonstrated the reduction of side reactions on the surface of the cathode material. In conclusion, PVP was successfully introduced into the NCM surface, whose positive role of the coordination anchoring effect was directly confirmed, and surface modification did not affect the valence environment of each element.…”

“…Finding excellent cathode materials with long cycle life, excellent energy density, and high rate performance has always been the focus of researchers. [5][6][7] LiCoO 2 , as the initial cathode material, was transformed from the hexagonal crystal system to a monoclinic crystal system under high voltage, and its structural stability was damaged, resulting in a rapid decline in capacity. [8,9] Spinel LiMn 2 O 4 has a low specific capacity, and the Jahn-Teller effect leads to a decrease in cyclic stability.…”

“…Furthermore, Figure5c,dshows the XPS spectra of O 1s and C 1s, respectively. Compared with NCM, the lattice oxygen content of P2-NCM was significantly increased, indicating that the dissolution of transition metal ions was effectively inhibited [5,43]. In addition, the lower content of CO2- 3 further demonstrated the reduction of side reactions on the surface of the cathode material.…”

Magnetic Frustration Effect on the Rate Performance of LiNi0.6Co0.4−xMnxO2 Cathodes for Lithium‐Ion Batteries

“…Additionally, the distinct layered structure can also be verified by the observed splitting of the (006)/(012) and (018)/(110) peaks (Figure 3c). [ 28 ] One point worth mentioning here is that the (003) and (110) planes are believed to correspond to the lattice parameters in the c ‐axis and a ‐axis directions, respectively. [ 29 ] As shown in Figure 3d, among these five samples, their diffraction peaks of (003) and (110) planes shift to lower angle with the increase of Mn content, substantiating the progressive enlargement of lattice along both c ‐axis and a ‐axis, which can also be testified by the Rietveld refinement results (Figure S6 and Table S2, Supporting Information).…”

Ultrahigh Capacity Retention of a Li2ZrO3-Coated Ni-Rich LiNi0.8Co0.1Mn0.1O2 Cathode Material through Covalent Interfacial Engineering

“…Nowadays, lithium-ion batteries (LIBs) have been widely used in various portable electronic devices, energy storage systems, and electric vehicles (EVs) due to the relatively well-balanced performances, including high energy density and long cycle life. − The fast-growing EV market has set a higher standard for the specific capacity, cycle stability, and thermal stability of LIBs. This places an essential requirement on cathode materials , since the overall performances of a whole battery are primarily determined by cathode materials in current battery technology.…”