We have developed semi-continuous fluidized bed chemical vapor deposition method [1], which yields submillimeter-long few-wall CNTs with carbon purity >99 wt% and metal impurity <0.1 wt% [2]. By capturing capacitive particles (99 wt%) with CNTs (1 wt%), a lithium ion full cell with graphite-CNT anode and LiCoO₂-CNT cathode is demonstrated (Figure 1b) [3]. This platform is also effective to create electrodes of the emerging active materials such as Si anode [4] and S cathode [5] with practically high gravimetric, areal, and volumetric loadings, and realized Li_xSi-S and Li-Li₂S_x full cells [6,7]. In addition, by combining with the insulative sponge of boron nitride nanotubes (BNNTs), the graphite-CNT|BNNT| LiCoO₂-CNT full cell with high thermal stability was developed [8].

[1] D.Y. Kim, et al., Carbon 49, 1972 (2011).
[2] Z. Chen, et al., Carbon 80, 339 (2014).
[3] K. Hasegawa and S. Noda, J. Power Sources 321, 155 (2016).
[4] T. Kowase, et al., J. Power Sources 363, 450 (2017).
[5] K. Hori, et al., J. Phys. Chem. C 123, 3951 (2019).
[6] K. Hori, et al., Carbon 161, 612-621 (2020).
[7] Y. Yoshie, et al., Carbon 182, 32-41 (2021).
[8] K. Kaneko, et al., Carbon 167, 596-600 (2020).

Figure 1. (a) Semi-continuous production of submillimeter-long few-wall CNTs by fluidized bed [1]. (b) Lithium ion full cell made of graphite-CNT anode and LiCoO₂-CNT cathode [3].