全干法合成锂离子电池用高镍三元单晶颗粒及性能
All-dry solid-phase synthesis of single-crystalline Ni-rich ternary cathodes for lithium-ion batteries
秦理 1余海峰 2姜昕 1陈灵 1程起林 1江浩3
作者信息
- 1. Shanghai Engineering Research Center of Hierarchical Nanomaterials,School of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China
- 2. Key Laboratory for Ultrafine Materials of Ministry of Education,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China
- 3. Shanghai Engineering Research Center of Hierarchical Nanomaterials,School of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China;Key Laboratory for Ultrafine Materials of Ministry of Education,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China
- 折叠
摘要
单晶型高镍三元层状氧化物凭借高能量密度、长循环寿命和优异的安全性成为新一代锂离子电池理想的正极材料.目前,单晶型高镍三元正极通过"共沉淀+高温锂化"两步制备,不仅工艺繁琐、原材料选择单一,制备过程还会产生大量废水/气.本文提出了一种新的全干法固相合成策略,实现了单晶型高镍三元正极低成本、无废水绿色制备.在煅烧过程引入锶/钛离子作为烧结助剂,降低烧结温度来缓解锂/氧流失,从而降低锂镍混排并稳定晶格氧.此外,针对固相合成过程锂化动力学缓慢导致表面残碱较高的问题,引入硼化合物与残碱反应,不仅有效提升了界面稳定性,而且形成的离子导体还能够加速锂离子在界面处的迁移.因此,制备的单晶型高镍三元正极在0.1 C电流密度下比容量可达到191.1 mA h g-1,以1 C电流密度在软包全电池中循环500次后仍具有90.1％的容量保持率.
Abstract
Single-crystalline ternary cathodes prepared through all-dry solid-phase synthesis(ADSPS)are perceived as prominent candidates for lithium-ion batteries(LIBs)be-cause they are inexpensive and effluent-free.However,the aggravated lithium/oxygen(Li/O)loss and sluggish lithiation process during sintering result in an unstable layered struc-ture and a large amount of surface residual alkali.Herein,a lithium borate(LBO)-coated and strontium/titanium(Sr/Ti)co-doped single-crystalline nickel(Ni)-rich ternary cathode with a highly ordered layered structure is prepared via ADSPS for the first time.The synergistic effect of Sr/Ti ions con-siderably promotes grain growth with decreased lithiation temperature,which alleviates the Li/Ni disorder and stabilizes the lattice O.After coating with a layer of LBO,the surface residual alkali has been considerably depleted with favorable Li-ion transfer at the interface.Consequently,the as-obtained cathode delivers a high reversible capacity of 191.1 mA h g-1 at 0.1 C in coin-type half cells and superior retention of 90.1％after 500 cycles at 1 C in pouch-type full cells.The unique insight and strategy in this research will promote the appli-cation of ADSPS in single-crystalline Ni-rich ternary cathodes for LIBs.
关键词
Ni-rich cathodes/all-dry solid-phase synthesis/structural stability/interface modification/Li-ion batteriesKey words
Ni-rich cathodes/all-dry solid-phase synthesis/structural stability/interface modification/Li-ion batteries引用本文复制引用
基金项目
National Natural Science Foundation of China(U22A20429)
National Natural Science Foundation of China(22308103)
China Postdoctoral Science Foundation(2023M731083)
Fundamental Research Funds for the Central Universities()
出版年
2024
NETL
NSTL
万方数据