| 7 | 1/1 | 返回列表 |
| 查看: 1408 | 回復: 6 | |||
zhangj199305新蟲 (小有名氣)
|
[交流]
說capacity 會隨著current density 增大而降低? 已有6人參與
|
|
電化學初學者,有一問題向各位請教一下: 最近在一篇Goodenough文章中看到這么一個結(jié)論,說隨著current density的提高,電池的capacity會隨之下降。 按照文中解釋是說,當外電路的electronic current density 較小時,可以與電池內(nèi)部的ionic current density達到平衡,但是當ionic current density 到達極限時,增大electronic current density之后,capacity就會降低。我不是很能夠理解他的capacity是根據(jù)什么來算的? 原文如下: ”capacity decreases with the rate of charge or discharge, i.e. the magnitude of the electronic current in the external circuit, which must be matched by the internal ionic current within the battery. Since the ionic current density of the electrolyte and electrodes, including the rate of ion transfer across the electrode/electrolyte interface, is much smaller than the electronic current density, the electrodes and electrolyte have a large surface are and a small thickness. Nevertheless, at high current densities, the ionic motion within an electrode and/or across an electrode/electrolyte interface is too slow for the charge distribution to reach equilibrium, which is why the reversible capacity decreases with increasing current density in battey. -- Chem. Mater., Vol. 22, No. 3, 2010 (Challenges for rechargeable batteries) |
木蟲 (正式寫手)

版主 (著名寫手)
木蟲 (著名寫手)

木蟲 (著名寫手)

|
我認為這段話是在解釋電池驅(qū)動電路的“速率控制步驟”或“木桶短板理論”。相對于外電路而言,電池內(nèi)部的電流反應是控制步驟,電池內(nèi)部的電化學反應可以分為五步,其中文中說的電極/電解液界面處進行的是應該是指“氧化還原”亦即“電荷轉(zhuǎn)移”過程,這個過程在五步中是最慢的,是電池內(nèi)部乃至整個電路的控制步驟和短板。電流越大前一步的產(chǎn)物在這一步的反應端積聚越多,該步無法達到平衡狀態(tài),導致極化增大直至達到充放電的截止電位,結(jié)果體現(xiàn)為電池放出的電量降低。 發(fā)自小木蟲Android客戶端 |

木蟲 (正式寫手)

| 7 | 1/1 | 返回列表 |
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 328求調(diào)劑,英語六級551,有科研經(jīng)歷 +6 | 生物工程調(diào)劑 2026-03-17 | 10/500 |
|
|---|---|---|---|---|
|
[考研] 315分,誠求調(diào)劑,材料與化工085600 +3 | 13756423260 2026-03-22 | 3/150 |
|
|
[考研] 能源材料化學課題組招收碩士研究生8-10名 +5 | 脫穎而出 2026-03-16 | 17/850 |
|
|
[考研] 260求調(diào)劑 +3 | 朱芷琳 2026-03-20 | 4/200 |
|
|
[考研] 求調(diào)劑 +7 | Auroracx 2026-03-22 | 7/350 |
|
|
[考研] 285求調(diào)劑 +6 | ytter 2026-03-22 | 6/300 |
|
|
[考研] 生物學一志愿985,分數(shù)349求調(diào)劑 +4 | zxts12 2026-03-21 | 7/350 |
|
|
[考研] 初試 317 +7 | 半拉月丙 2026-03-20 | 7/350 |
|
|
[考研] 0805 316求調(diào)劑 +3 | 大雪深藏 2026-03-18 | 3/150 |
|
|
[考研] 材料學碩333求調(diào)劑 +3 | 北道巷 2026-03-18 | 3/150 |
|
|
[考研] 265求調(diào)劑 +3 | Jack?k?y 2026-03-17 | 3/150 |
|
|
[考研] 301求調(diào)劑 +10 | yy要上岸呀 2026-03-17 | 10/500 |
|
|
[考研] 化學求調(diào)劑 +4 | 臨澤境llllll 2026-03-17 | 5/250 |
|
|
[考研] 一志愿中國石油大學(華東) 本科齊魯工業(yè)大學 +3 | 石能偉 2026-03-17 | 3/150 |
|
|
[考研] 296求調(diào)劑 +6 | www_q 2026-03-18 | 10/500 |
|
|
[考研] 321求調(diào)劑 +9 | 何潤采123 2026-03-18 | 11/550 |
|
|
[考研]
|
然11 2026-03-19 | 4/200 |
|
|
[考研] 一志愿西安交通大學 學碩 354求調(diào)劑211或者雙一流 +3 | 我想要讀研究生 2026-03-20 | 3/150 |
|
|
[碩博家園] 湖北工業(yè)大學 生命科學與健康學院-課題組招收2026級食品/生物方向碩士 +3 | 1喜春8 2026-03-17 | 5/250 |
|
|
[考研]
|
zhouzhen654 2026-03-16 | 3/150 |
|