DMF stabilized Li3N slurry for manufacturing self-prelithiatable lithium-ion capacitors

Cuilian Liu; Tianyu Li; Hongzhang Zhang; Zihan Song; Chao Qu; Guangjin Hou; Huamin Zhang; Chuanfa Ni; Xianfeng Li

doi:10.1016/j.scib.2019.11.014

DMF stabilized Li₃N slurry for manufacturing self-prelithiatable lithium-ion capacitors

Sci Bull (Beijing). 2020 Mar 30;65(6):434-442. doi: 10.1016/j.scib.2019.11.014. Epub 2019 Nov 18.

Authors

Cuilian Liu¹, Tianyu Li¹, Hongzhang Zhang², Zihan Song¹, Chao Qu¹, Guangjin Hou³, Huamin Zhang¹, Chuanfa Ni⁴, Xianfeng Li⁵

Affiliations

¹ Division of Energy Storage, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
² Division of Energy Storage, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. Electronic address: zhanghz@dicp.ac.cn.
³ Solid-state NMR & Catalytic Chemistry Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
⁴ Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
⁵ Division of Energy Storage, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. Electronic address: lixianfeng@dicp.ac.cn.

PMID: 36747432
DOI: 10.1016/j.scib.2019.11.014

Abstract

Li₃N is an excellent zero-residue positive electrode pre-lithiation additive to offset the initial lithium loss in lithium-ion capacitors. However, Li₃N has an intrinsic problem of poor compatibility with commonly used aprotic polar solvents in electrode manufacture procedure due to its high reactivity with commonly used solvents like N-methy-2-pyrrolidone (NMP) and etc. It is the Valley of Death between research and large-scale commercialization of Li-ion capacitors using Li₃N as prelithiation agent. In this work, Li₃N containing electrode is prepared by a commercially adoptable route for the first time, using N,N-dimethylformamide (DMF) to homogenate the electrode slurry. The DMF molecular stabilizing mechanism is confirmed via experiment analysis and DFT simulation, indicating that the dehydrogenation energy for DMF is obviously larger than other commonly used solvents such as NMP and etc. The soft package lithium-ion capacitors (LIC250) with only 12 wt% Li₃N addition in AC positive electrode exhibits excellent rate capability, cyclic stability and ultrahigh specific energy. Its specific energy is 2.3 times higher than the Li₃N-free devices, with energy retention as high as 90% after 10,000 cycles.

Keywords: High specific energy and long cycle life; Li(3)N; Lithium-ion capacitors; Pre-lithiation; Soft package.