Improvement of high-rate performance of LiFePO4 cathode with through-holed LiFePO4/Activated carbon hybrid electrode structure fabricated with a pico-second pulsed laser

Improvement in Rate Capabilities of Hybrid Cathodes with Through‐Holed Layers of Cathode Material and Activated Carbon on Each Side of a Current Collector in Lithium‐Ion Batteries.

“…The cross‐sections of the LFP/AC and NMC/AC HCs were obtained with FE–SEM (Figure 5). Similar to the through‐holed LFP/AC HC and LFP/LFP cathodes shown in our papers [13–15] and as expected from the surface SEM image of through‐holed LFP/AC and NMC/AC HCs in Figures 3 and 4, the cross‐sectional shapes of holes formed on the side of laser incidence was mortar‐shaped; the smallest hole size was at the position of the CCs. The degree of the tapered shape was different between the LFP/AC and NMC/AC HCs.…”

“…In our previous paper, [13] we reported only the rudimentary performance of the through‐holed HCs. In this paper, we show the dependence of HC performance on the weight percentage of AC relative to the total weight of the active materials of AC and LIB cathode materials on CC surfaces, a comparison of the charge and discharge behaviors of the HCs, the difference in HC performance resulting from changing the type of LIB cathode material, and a comparison of the HCs in the full discharging process without an open circuit period.…”

“…In addition, based on the idea of through‐holed cathodes, we have fabricated through‐holed hybrid cathodes (HCs) composed of lithium ferrophosphate (LiFePO 4 ; LFP)/activated carbon (AC). The enhanced rate capability of the HCs can be realized [13,14] . One side of a current collector (CC) is coated with LFP, and AC is fixed on the other side.…”

An Improved High-rate Discharging Performance of “Unbalanced” LiFePO₄ Cathodes with Different LiFePO₄ Loadings by a Grid-patterned Micrometer Size-holed Electrode Structuring

“…0.7-1.0, 1.9-2.1, 3.6-4 and 5.6-6 mg cm ¹2 (Table 1). Holing and characterization of these LFP/LFP cathodes was conducted using a picosecond pulsed laser as described previously [25][26][27][28] (see 1.2 and 1.3 in the SI). Table 1 lists 23 LFP/LFP cathodes examined in this study and hereafter the individual cathodes will be denoted as No.…”

“…This larger discharging capacity retention of the holed cathodes can be considered to reflect the fact that a facilitated transfer of Li + ions in the discharging process can occur through both the surface and the sidewalls (produced by forming the holes) of the LFP layer (or LFP/current collector layers), as found recently for the LFP/LFP cathode with the same LFP thickness on both side of a current collector [25][26][27] and the LFP/activated carbon (AC) cathode (in which the thicknesses of LFP and AC layers are different). 28 Table 1.…”