Dual-component LixTiO2@silica functional coating in one layer for performance enhanced LiNi0.6Co0.2Mn0.2O2 cathode

Selective TiO2 Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

“…Peaks at each 2 θ position, which are sharp with high intensities, indicate that the high crystallinity of the materials is maintained during the entire coating process. In particular, peak splitting for (0 0 6)/(0 1 2) and (1 0 8)/(1 1 0) peaks at 38 and 65° indicates a highly ordered structure . Meanwhile, the intensity ratio of I (0 0 3) / I (1 0 4) reflects the cation mixing degree of nickel‐rich layered oxides, and the TiO 2 ‐PNCM sample shows a ratio of 1.26 whereas bare NCM reveals 1.28; both values are generally allowed (≥1.2) .…”

Surface/Interface Structure Degradation of Ni‐Rich Layered Oxide Cathodes toward Lithium‐Ion Batteries: Fundamental Mechanisms and Remedying Strategies

“…Now that the parasitic side reactions start from the interfaces between the solid cathodes and liquid electrolytes, the most effective method is to avoid their direct contact by introducing passive physical protection layer on the cathode surface . In general, the employed coating species can be categorized into i) the chemically and electrochemically inactive coatings, including metal oxides (Al 2 O 3 , TiO 2 , MgO, SiO 2 , ZrO 2 , V 2 O 5 , Nb 2 O 5 , ZnO, MoO 3 , and Y 2 O 3 ,) and phosphates (AlPO 4 , MnPO 4 , Mn 3 (PO 4 ) 2 , La(PO 4 ) 3 , Ni 3 (PO 4 ) 2 , Co 3 (PO 4 ) 2 , ZrP 2 O 7 , and FePO 4 ) as well as some fluorides (AlF 3 and LiF); ii) the Li + conductive coatings, mainly refer to the Li‐containing compounds such as LiAlO 2 , Li 2 ZrO 3 , Li 3 VO 4 , Li 2 MnO 3 , LiMn 2 O 4 , Li 3 PO 4 (LPO), LiFePO 4 (LFP), LiMnPO 4 , Li 2 TiO 3 , LiTiO 2 , Li 2 O‐2B 2 O 3 , LiTi 2 (PO 4 ) 3 , LiZr 2 (PO 4 ) 3 , Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 , Li 0.5 La 0.5 TiO 3 , LiTaO 3 , Li 4 SiO 4 , and LiAlF 4 as well as some heterostructured electrochemical active cathodes (Li 1.2 Ni 0.2 Mn 0.6 O 2 , Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 and NCM333); and iii) the electron conducting coating, representatively, reduced graphene oxide (rGO), permeable poly (3,4‐ethylenedioxythiophene) (PEDOT),…”

“…In particular, the capacity retention of the NCM622 at a high cutoff voltage of 4.7 V is effectively improved owing to the LiAlO 2 coating (Figure b) . Expectedly, the Li x TiO 2 (0 ≤ x ≤ 1) with a rapid Li + insertion/extraction along (001) plane is reasonably chosen as a coating layer on the NCM622 cathode, which can not only restrain the side reactions, but also hugely improve the Li‐ion diffusion coefficient at the interface, thus resulting in the upgraded electrochemical properties . The Li 2 ZrO 3 , Li 4 SiO 4 , and Li 3 VO 4 as well as other Li‐containing compounds with high Li + conductivity have all been successfully examined as the appealing coating layers for the Ni‐rich cathodes .…”

Rational Design of a Piezoelectric BaTiO3 Nanodot Surface‐Modified LiNi0.6Co0.2Mn0.2O2 Cathode Material for High‐Rate Lithium‐Ion Batteries

“…All samples can be well indexed to the α-NaFeO 2 structure (space group, R-3m) and the apparent splitting of (006)/(102) and (108)/(110) peaks indicates that each sample has high crystallinity of layered structure. [28,29] It is worth noting after the modification that there are no impurity peaks and distinct variations of (003) peaks according to the magnified view, suggesting that (i) No characteristic peaks appear due to the small amount of BTO. (ii) The crystal structure of pristine NCM622 is not affected by the modification process.…”