Abstract:As everal atomic layers thick magnesium fluoride (MgF 2 )f ilm is successfully deposited onto each individual grain of an ultrahigh-potential LiMn 1.5 Ni 0.5 O 4 -powder material for Li-ion batteries. The resulting film has am arked protection action, as it does not compromise the cathode performance substantially,w hile it extends the cycle life of the cathodes prepared from the coatedp owder.T he protective effect is pronounceda t4 58Ca nd the catastrophicc apacity fading is halted. The essence of the protec… Show more
“…Hence, it is prerequisite to develop novel strategies for surface coating materials by considering their compatibility with the electrolyte/electrolyte additives and the bulk of host (LiCoO 2 ) even at the high charge cut‐off voltage. For instance, Kraytsberg et al successfully coated MgF 2 on as‐prepared spinel LiMn 1.5 Ni 0.5 O 4 powder using the ALD technique, and this strategy enhanced the electrochemical performance of the spinel cathode material, even at the high cut‐off voltage of 4.7 V (vs Li) and high operating temperature (45 °C), by mitigating the possible undesirable side reactions of electrode material with the electrolyte, as the ALD‐based MgF 2 film acts as a protective layer. Such ALD‐based coating strategies could be employed for LiCoO 2 and other cathode materials to achieve high energy density under adverse operating conditions.…”
Section: Conclusion and Critical Opinionsmentioning
Battery industries and research groups are further investigating LiCoO2 to unravel the capacity at high‐voltages (>4.3 vs Li). The research trends are towards the surface modification of the LiCoO2 and stabilize it structurally and chemically. In this report, the recent progress in the surface‐coating materials i.e., single‐element, binary, and ternary hybrid‐materials etc. and their coating methods are illustrated. Further, the importance of evaluating the surface‐coated LiCoO2 in the Li‐ion full‐cell is highlighted with our recent results. Mg,P‐coated LiCoO2 full‐cells exhibit excellent thermal stability, high‐temperature cycle and room‐temperature rate capabilities with high energy‐density of ≈1.4 W h cc−1 at 10 C and 4.35 V. Besides, pouch‐type full‐cells with high‐loading (18 mg cm−2) electrodes of layered‐Li(Ni,Mn)O2 ‐coated LiCoO2 not only deliver prolonged cycle‐life at room and elevated‐temperatures but also high energy‐density of ≈2 W h cc−1 after 100 cycles at 25 °C and 4.47 V (vs natural graphite). The post‐mortem analyses and experimental results suggest enhanced electrochemical performances are attributed to the mechanistic behaviour of hybrid surface‐coating layers that can mitigate undesirable side reactions and micro‐crack formations on the surface of LiCoO2 at the adverse conditions. Hence, the surface‐engineering of electrode materials could be a viable path to achieve the high‐energy Li‐ion cells for future applications.
“…Hence, it is prerequisite to develop novel strategies for surface coating materials by considering their compatibility with the electrolyte/electrolyte additives and the bulk of host (LiCoO 2 ) even at the high charge cut‐off voltage. For instance, Kraytsberg et al successfully coated MgF 2 on as‐prepared spinel LiMn 1.5 Ni 0.5 O 4 powder using the ALD technique, and this strategy enhanced the electrochemical performance of the spinel cathode material, even at the high cut‐off voltage of 4.7 V (vs Li) and high operating temperature (45 °C), by mitigating the possible undesirable side reactions of electrode material with the electrolyte, as the ALD‐based MgF 2 film acts as a protective layer. Such ALD‐based coating strategies could be employed for LiCoO 2 and other cathode materials to achieve high energy density under adverse operating conditions.…”
Section: Conclusion and Critical Opinionsmentioning
Battery industries and research groups are further investigating LiCoO2 to unravel the capacity at high‐voltages (>4.3 vs Li). The research trends are towards the surface modification of the LiCoO2 and stabilize it structurally and chemically. In this report, the recent progress in the surface‐coating materials i.e., single‐element, binary, and ternary hybrid‐materials etc. and their coating methods are illustrated. Further, the importance of evaluating the surface‐coated LiCoO2 in the Li‐ion full‐cell is highlighted with our recent results. Mg,P‐coated LiCoO2 full‐cells exhibit excellent thermal stability, high‐temperature cycle and room‐temperature rate capabilities with high energy‐density of ≈1.4 W h cc−1 at 10 C and 4.35 V. Besides, pouch‐type full‐cells with high‐loading (18 mg cm−2) electrodes of layered‐Li(Ni,Mn)O2 ‐coated LiCoO2 not only deliver prolonged cycle‐life at room and elevated‐temperatures but also high energy‐density of ≈2 W h cc−1 after 100 cycles at 25 °C and 4.47 V (vs natural graphite). The post‐mortem analyses and experimental results suggest enhanced electrochemical performances are attributed to the mechanistic behaviour of hybrid surface‐coating layers that can mitigate undesirable side reactions and micro‐crack formations on the surface of LiCoO2 at the adverse conditions. Hence, the surface‐engineering of electrode materials could be a viable path to achieve the high‐energy Li‐ion cells for future applications.
“…Kraytsberg et al [116] successfully deposited a several atomic layer thick uniform magnesium fluoride film onto LNMO powders by ALD techniques. Whereas the film moderately diminished initial cathode performance, it substantially extended the cycle life of the LNMO cathodes.…”
Section: Approaches To Improve the Cycling Stability Of Lnmomentioning
confidence: 99%
“…The improvements were attributed to the fact that the GaF 3 layer not only increased the electronic conductivity of the LNMO but also effectively suppressed the undesired reaction between the LNMO and the electrolytes, which reduced the charge-transfer impedance and the dissolution of Ni and Mn during cycling.Fig. 8Capacity versus cycle number for bare LMNO material and ALD-coated LMNO material (12 ALD-layer coating, C/10 rate): a room temperature, b 45 °C [116]
…”
Section: Approaches To Improve the Cycling Stability Of Lnmomentioning
confidence: 99%
“…Capacity versus cycle number for bare LMNO material and ALD-coated LMNO material (12 ALD-layer coating, C/10 rate): a room temperature, b 45 °C [116]…”
Section: Approaches To Improve the Cycling Stability Of Lnmomentioning
High-voltage lithium-ion batteries (HVLIBs) are considered as promising devices of energy storage for electric vehicle, hybrid electric vehicle, and other high-power equipment. HVLIBs require their own platform voltages to be higher than 4.5 V on charge. Lithium nickel manganese spinel LiNi0.5Mn1.5O4 (LNMO) cathode is the most promising candidate among the 5 V cathode materials for HVLIBs due to its flat plateau at 4.7 V. However, the degradation of cyclic performance is very serious when LNMO cathode operates over 4.2 V. In this review, we summarize some methods for enhancing the cycling stability of LNMO cathodes in lithium-ion batteries, including doping, cathode surface coating, electrolyte modifying, and other methods. We also discuss the advantages and disadvantages of different methods.
“…The fluorides currently used for coating include AlF 3 , MgF 2 , CaF 2 , YF 3 , LaF 3 , GaF 3 , and LiF [71][72][73][74][75]. Lee et al [76] mixed the homemade AlF 3 with NCA and obtained the NCA/AlF 3 material after high-speed ball milling (3400 r/min) for 5 min.…”
Ternary nickel-cobalt lithium aluminate LiNi x Co y Al 1-x-y O 2 (NCA, x ≥ 0:8) is an essential cathode material with many vital advantages, such as lower cost and higher specific capacity compared with lithium cobaltate and lithium iron phosphate materials. However, the noticeably irreversible capacity and reduced cycle performance of NCA cathode materials have restricted their further development. To solve these problems and further improve the electrochemical performance, numerous research studies on material modification have been conducted, achieving promising results in recent years. In this work, the progress of NCA cathode materials is examined from the aspects of surface coating and bulk doping. Furthermore, future research directions for NCA cathode materials are proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
