DMF stabilized LiN slurry for manufacturing self-prelithiatable lithium-ion capacitors.

LiN is an excellent zero-residue positive electrode pre-lithiation additive to offset the initial lithium loss in lithium-ion capacitors. However, LiN 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 LiN as prelithiation agent. In this work, LiN 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% LiN 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 LiN-free devices, with energy retention as high as 90% after 10,000 cycles.