amandla e-electromotive
◆Ukukhipha ukusebenza kwamabhethri okugcina amandla
Uma isifunda sangaphandle sivuliwe, okusho ukuthi awekho amandla agelezayo ebhethrini, umehluko ongaba khona phakathi kwama-electrode e-positive kanye ne-negative uchazwa ngokuthi amandla ebhethri ebhethri (EMF), ngokuvamile achazwa ngophawu E. Inani le-EMF lingenye yezinkomba ezibonisa inani lamandla kagesiuhlelo lwebhethrikungaba okukhiphayo. Ngokwezimiso ze-thermodynamic, sine...
Kufomula, i-AG imele ushintsho kumandla wamahhala we-Gibbs; n imele inombolo yokudlulisa i-electron; U-E umelela amandla e-electromotive cell; futhi F imele Faraday njalo.
Isibalo (1.2) sibonisa ukuthi ubukhulu bamandla ebhethri e-electromotive ikakhulukazi buncike ezicini zemvelo zezinto ezihilelekile ekuphenduleni kwamakhemikhali, izimo zokusabela (ezifana nezinga lokushisa) ngesikhathi sokusebenza kwebhethri, kanye nomsebenzi wamareactants nemikhiqizo, futhi akuthintwa ijometri noma usayizi webhethri.
Vula i-voltage yesifunda
I-voltage evuliwe-yesiyingi yebhethri isho umehluko ongaba khona phakathi kwamatheminali aphozithivu noma anegethivu lapho isifunda sangaphandle sinqanyulwa ebhethrini. Kubalulekile ukuqaphela ukuthi ngenxa yokuthi amatheminali aphozithivu noma anegethivu kungenzeka awafikanga ku-thermodynamic equilibrium esixazululweni se-electrolyte, i-voltage evulekile-yesiyingi ngokuvamile iba ngaphansi kancane kunamandla ayo e-electromotive (EMF). I-EMF inani lethiyori elibalwe ngokusekelwe kumafomula e-thermodynamic, kuyilapho amandla kagesi{4}}esiyingi avulekile iyinani langempela elitholwe ngokulinganisa kokuhlola okuqondile; lezi ezimbili zisondelene kakhulu ngenani. Ukuze unqume ngokunembile amandla -esiyingi esivulekile, awekho amandla okufanele ageleze ensimbini yokulinganisa phakathi nenqubo yokulinganisa; i-voltmeter ephezulu-evame ukusetshenziselwa lokhu kuhlolwa.
Ngaphezu kwalokho, umqondo we-voltage yegama nawo uyasetshenziswa ocwaningweni lokukhiqiza. I-voltage yegama isilinganiso esifanele se-voltage yebhethri, eyaziwa nangokuthi i-voltage elinganiselwe, futhi isetshenziselwa ukuhlonza uhlobo lwebhethri. Isibonelo, amandla -esiyingi segesi evulekile{{3}yebhethri ye-asidi isondele ku-2.1V, futhi i-voltage yayo encane isethwe ku-2.0V; amandla kagesi we-zinc-ibhethri le-manganese ngu-1.5V; kanye ne-voltage yegama lebhethri le-cadmium{8}}nickel kanye nebhethri ye-nickel{9}}yensimbi ye-hydride ingu-1.2V.
Ukumelana kwangaphakathi
Ukumelana kwangaphakathi kwebhethri, okuvame ukubizwa ngokuthi ukumelana kwangaphakathi (Ryangaphakathi), isho ukumelana okuhlangabezana nakho lapho ibhethri ligeleza. Lokhu kumelana kwangaphakathi ikakhulukazi kuqukethe izingxenye ezimbili: eyodwa ukumelana kwangaphakathi kwe-ohmic okubangelwa izakhiwo zezinto ngokwazo; enye i-polarization eyengeziwe ukumelana kwangaphakathi okukhiqizwa yi-polarization phenomenon endaweni ye-electrode ngesikhathi sokusabela kwe-electrochemical.
Ukumelana ne-ohmic (R0) kuthintwa izici ze-electrolyte, izakhiwo ze-membrane, nezinto ze-electrode. Ukumelana ne-ohmic kwesisombululo se-electrolyte kuhlobene eduze nokwakheka kwaso okukhethekile, izinga lokuhlushwa, kanye nezinga lokushisa elizungezile. Ngokuvamile, ukugxiliswa kwe-electrolyte kwamabhethri kukhethwa ngaphakathi kwebanga lokuhamba okuphezulu kakhulu. Ukumelana okubangelwa ama-membrane micropores ekufudukeni kwama-ion e-electrolyte kubizwa ngokuthi ukumelana nolwelwesi, okungukuthi, ukumelana okutholwa ama-ion njengoba edlula kuma-micropores olwelwesi. Ukuphikiswa kwe-ohmic kwe-membrane kuhlobene nezici ezifana nohlobo lwe-electrolyte, i-membrane material, i-porosity, kanye nezinga le-pore tortuosity. Ukumelana-kwesigaba esiqinile kuma-electrodes kufaka phakathi ukumelana kwezinhlayiya zento esebenzayo ngokwazo, ukumelana nokuxhumana phakathi kwezinhlayiya, ukumelana nokuxhumana phakathi kwezinto ezisebenzayo nohlaka lwe-conductive, kanye nesamba sokumelana kohlaka lwe-conductive, amabhasi e-conductive, namatheminali. Ngesikhathi sokukhishwa, ukubunjwa kanye ne-morphology yezinto ezisebenzayo zingashintsha, okuholela ekushintsheni okuphawulekayo kokumelana. Ukuze kuncishiswe{10}}ukumelana nesigaba esiqinile, izakhi ze-conductive, njenge-acetylene black{11}}graphite, zivame ukungezwa kokokusebenza okusebenzayo ukuze kwandiswe ukusebenza kwayo. Ukumelana ne-ohmic kwangaphakathi kwebhethri nakho kuhlobene nezici ezifana nosayizi walo, ukuhlanganisa, nokwakheka. Uma umhlangano uminyene kakhulu futhi kuba kuncane isikhala se-electrode, kunciphisa ukumelana kwangaphakathi kwe-ohmic.
Ukumelana ne-polarization (R) kubhekisela ekuphikiseni kwangaphakathi okukhiqizwa kumthombo wamandla wekhemikhali ngenxa ye-polarization phakathi nokusabela kwe-electrochemical kuma-electrode aqondile noma angalungile. Ukumelana ne-polarization kufaka phakathi isamba sokumelana okubangelwa i-electrochemical polarization kanye ne-concentration polarization. Ubukhulu bayo buthonywa izici zezinto ezisebenzayo, isakhiwo se-electrode, nenqubo yokukhiqiza ibhethri, futhi ihlobene kakhulu nesimo sokusebenza kwebhethri. Ngakho-ke, ukumelana ne-polarization kushintsha ngokufanele ngokuhlukahluka kwemodi yokukhipha kanye nesikhathi sokukhipha.
I-voltage yokusebenza
I-voltage yokusebenza yebhethri, eyaziwa nangokuthi i-voltage yokulayisha noma i-voltage yokukhipha, ibhekisela emehlukweni ongaba khona phakathi kwamatheminali avumayo noma angalungile ebhethri lapho ibhethri ligeleza kwisekethe yangaphandle. Uma i-current igeleza kubhethri, ukuze unqobe ukumelana okubangelwa ukumelana ne-polarization kanye nokumelana ne-ohmic, inani langempela le-voltage elinganisiwe yokusebenza lihlala liphansi kune-voltage evuliwe-yesiyingi ngaphansi{2}}kwezimo zokulayisha.
Njengoba kungabonwa esilinganisweni (1.3), kukhulu ukumelana nebhethri kwangaphakathi, kwehlisa i-voltage yokusebenza yebhethri, kanye nokukhipha amandla kwangempela kuncane. Ngokusobala, ukumelana kwangaphakathi kwebhethri kufanele kube kuncane ngangokunokwenzeka.