## 抄録

A very-high-energy-density Li-ion capacitor (LIC) was developed using commercially available activated carbon (AC) having a high surface area of 3041 m^{2} g^{−1} and conventional 2 μm-sized Si as the cathode and anode material, respectively, at an AC:Si mass ratio of 6.37. The LIC delivered a maximum energy density of 400 Wh kg^{−1} at a power density of 32 W kg^{−1} and exhibited excellent rate stability (200 Wh kg^{−1} at 6 kW kg^{−1}) over the cell voltage range of 1.0−4.3 V; these values were based on the total mass of the active materials in the cathode (AC) and anode (Si). However, its low cycling stability induced a 79.9% decrease in its energy density (278 to 56 Wh kg^{−1}) following 1000 cycles at ∼650 W kg^{−1}. The potential variations of the cathode and anode were investigated during charge/discharge cycling. Postmortem electrode analyses indicated that the anode permitted the delamination of Si particles and the formation of a thick passive solid electrolyte interphase layer (60 nm) mainly constituted of LiF. Reducing the cell voltage range to 2.0−4.0 V and the mass ratio to 3.30 reduced the energy density to 183 Wh kg^{−1} but improved the sustainability (176 to 156 Wh kg^{−1}, 88.6% retention) and maintained the power density (> 10 kW kg^{−1} at 100 Wh kg^{−1}) following 2000 cycles at ∼1 kW kg^{−1}.

本文言語 | 英語 |
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論文番号 | 139115 |

ジャーナル | Electrochimica Acta |

巻 | 394 |

DOI | |

出版ステータス | 出版済み - 20 10月 2021 |

外部発表 | はい |