Abstract
Surface modification of cathode (e.g., lithium layered oxide, NCM) has become ever more important in lithium-ion batteries, particularly for pursuing higher energy densities and safety at high voltage. This is because structural degradation of cathode can be mitigated significantly. Herein, an organic complex is introduced for metal phosphates (e.g., AlPO4) modification through a new film-forming process in non-aqueous solution. This general strategy overcomes the challenge of non-uniform coating in current precipitation method, then opens a new avenue towards ultra-thin surface modification on molecular scale. As one of examples, as-prepared AlPO4-coated NCM exhibits much improved structural and electrochemical stability; meanwhile, thermal runaway can be suppressed significantly in over-charged cell using the modified NCM, demonstrating higher and reliable safety features. The great improvements benefit from the uniform and ultrathin AlPO4 coating, which inhibits the collapse and conversion of layered structure to spinel especially to rock salt structure at high-voltage conditions, as confirmed by HRTEM and EELS.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 656-665 |
| Number of pages | 10 |
| Journal | ACS Energy Letters |
| Volume | 4 |
| Issue number | 3 |
| DOIs | |
| State | Published - Feb 8 2019 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: The research was supported by the funding of National Materials Genome Project (2016YFB0700600), National Natural Science Foundation Committee of China (Distinguished Youth Scientists Project of 51425301, U1601214, 51573013, 51773092 and 51772147). This work is supported by the National Natural Science Foundation of China (21521092, 21703285 and 11604130) and the Independent Research Project of the State Key Laboratory of Rare Earth Resources Utilization (110005R086), Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. The authors also thank the great support from the King Abdullah University of Science and Technology (KAUST).
