改善高溫鎳氫電池性能關鍵技術?
要怎么樣處理鎳氫電池在高溫環境出現的性能問題,是其能否在更大范疇使用的關鍵。鎳氫電池在充放電過程、使用環境中,必然要牽涉到溫度對電池性能和使用壽命的問題,特種設備急需的高容量移動電源、航天、航海、石油、煤炭、地質勘探及作業、冰上及登山體育項目用二次移動電源,具有很強的戰略意義、科學價值及經濟價值。另外,鎳氫動力鋰離子電池在燃料動力鋰電池+鎳氫電(dian)(dian)(dian)池(電(dian)(dian)(dian)電(dian)(dian)(dian)混(hun)合)及(ji)汽油+鎳氫電(dian)(dian)(dian)池(油電(dian)(dian)(dian)混(hun)合)等的混(hun)合動(dong)力(li)車(che)上也有緊(jin)要使用價值前(qian)景。
充電電池在充、放電過程(cheng),環境溫度的變化(hua)等(deng),對電池性能出現(xian)影響,雖然所有電池材(cai)料(liao)都(dou)對電池性能出現(xian)一(yi)(yi)定影響,然而,就(jiu)高溫電池來說,改(gai)善和優化(hua)正(zheng)(zheng)、負(fu)極(ji)材(cai)料(liao)是(shi)一(yi)(yi)種(zhong)比(bi)較好的辦(ban)法,除少量專利披露對貯氫(qing)合金進(jin)行(xing)改(gai)進(jin),緊要的技術還是(shi)在于(yu)正(zheng)(zheng)極(ji)材(cai)料(liao),包括(kuo)對電池正(zheng)(zheng)極(ji)材(cai)料(liao)配(pei)方時采用(yong)機械混合法添加稀土(tu)、稀有金屬、堿土(tu)元(yuan)素(su)(su)等(deng),如Mg、Ca、Sr、Sc、Y、La、鑭系元(yuan)素(su)(su)、Ti、Zr、Cr、Mo、W、Mn、Fe、Co、Cu、Zn、Cd、b、Al、Ga、In、Si、p、As、Sb、bi其(qi)中一(yi)(yi)種(zhong)或多種(zhong)氧(yang)化(hua)物(wu)、氫(qing)氧(yang)化(hua)物(wu)。由于(yu)正(zheng)(zheng)極(ji)配(pei)料(liao)時幾種(zhong)不(bu)同性質的物(wu)料(liao)很(hen)難達到完(wan)全平均,所以考(kao)慮在制造球(qiu)形氫(qing)氧(yang)化(hua)鎳時采用(yong)共沉淀(dian)摻雜上(shang)述(shu)元(yuan)素(su)(su),也有考(kao)慮在球(qiu)鎳上(shang)包覆一(yi)(yi)層上(shang)述(shu)元(yuan)素(su)(su)的氫(qing)氧(yang)化(hua)物(wu)。
盡管上述幾種辦法有關改善寬溫鎳氫電池性能起(qi)到一(yi)定的用途,依(yi)然存在不(bu)少欠(qian)缺和(he)不(bu)足,處理電(dian)池性能降(jiang)低(di)(di)的緊(jin)要辦法,一(yi)是改善球(qiu)鎳(nie)內部結構,戒備出(chu)現γ-NiOOH,希望β-NiOOH能與β-Ni(OH)2充(chong)(chong)放電(dian)時(shi)轉(zhuan)換容易(γ-NiOOH層間距為0.69nm,β-Ni(OH)2晶層間距約為0.46nm,β-NiOOH晶層間距約為0.48nm,γ-NiOOH的存在造成電(dian)極膨(peng)脹使活(huo)性材料損(sun)失,導(dao)電(dian)性降(jiang)低(di)(di),嚴(yan)重減(jian)少了(le)電(dian)極的循環壽命和(he)效率);另外辦法就是添加導(dao)電(dian)材料提(ti)高導(dao)電(dian)性能,加入CoO或Co(OH)2。但(dan)是,作(zuo)為原料粉(fen)末的氫氧化(hua)鈷(gu)在充(chong)(chong)放電(dian)過程中(zhong),一(yi)邊溶(rong)解于堿(jian)性水溶(rong)液中(zhong),一(yi)邊又再析出(chu),并(bing)且發生急劇的結構變化(hua),有(you)(you)部分鈷(gu)化(hua)合物(wu)游(you)離,造成鈷(gu)量(liang)變化(hua)導(dao)致(zhi)電(dian)池性能降(jiang)低(di)(di),雖(sui)然包覆球(qiu)鎳(nie)有(you)(you)關上述現象有(you)(you)了(le)一(yi)定的改善,但(dan)是依(yi)然存在包覆不(bu)夠(gou)牢固、充(chong)(chong)放電(dian)后出(chu)現表面(mian)層溶(rong)解和(he)脫落的現象。
梯度功能(neng)材(cai)料(liao)(liao)(FunctionaryGradientMaterials,FGM)是(shi)一種顯微組分(fen)、結(jie)構、性能(neng)階梯變化的高性能(neng)材(cai)料(liao)(liao)。具有較高機械強度、抗熱沖擊、耐高溫性能(neng)等(deng)特點。在(zai)電子(zi)部件(jian)、人(ren)造牙(ya)、汽車發(fa)動機、制動器、化工部件(jian)等(deng)有廣(guang)泛的使(shi)用(yong)。作者(zhe)認為(wei)將(jiang)梯度材(cai)料(liao)(liao)的原理與球鎳制造相結(jie)合將(jiang)成為(wei)高溫電池正極材(cai)料(liao)(liao)發(fa)展趨勢。
2、高溫(wen)鎳(nie)氫電(dian)池關鍵技術
2.1、正極材(cai)料的改良(liang)
2.1.1、正(zheng)極材料機械混(hun)合法(fa)
在(zai)電(dian)池配料時,通過機械混(hun)合法添加周期(qi)表(biao)中ⅡA、Ⅲb、Ⅳb、Ⅶb、Ⅷb、Ⅱb主族元素和3、4、5周期(qi)的(de)元素、氧化物(wu)或氫(qing)氧化物(wu),能(neng)(neng)較好地提高或改(gai)善鎳氫(qing)高溫性(xing)能(neng)(neng)。世界著名電(dian)池制造公司在(zai)華申(shen)請授權的(de)專(zhuan)利中多有解析,如日(ri)本松下、三洋;我國比亞迪(di);德國H.C.施(shi)塔克等公司。具體見下表(biao):
2.1.2、正極材料化學共(gong)沉淀法
將(jiang)上述元(yuan)素(su)在(zai)正極材料球(qiu)形氫(qing)氧(yang)(yang)化(hua)(hua)鎳加工過(guo)程,采用摻雜到(dao)層(ceng)狀結構氫(qing)氧(yang)(yang)化(hua)(hua)化(hua)(hua)鎳中(zhong),取(qu)代部分鎳離子,形成固溶(rong)體,使元(yuan)素(su)之間(jian)平均(jun)性(xing)(xing)更(geng)好;在(zai)球(qiu)形氫(qing)氧(yang)(yang)化(hua)(hua)鎳外面包覆一層(ceng)鈷的氫(qing)氧(yang)(yang)化(hua)(hua)物等(deng),有(you)(you)關(guan)提高電池整(zheng)體性(xing)(xing)能(neng),均(jun)有(you)(you)改善(shan)功能(neng)。具有(you)(you)代表(biao)性(xing)(xing)的專利見(jian)下表(biao):
2.2、負極材料(liao)的改(gai)良(liang)
鎳氫電池負極(ji)材料(liao)采用貯氫合金,緊要組成(cheng)元素為(wei)M(NiCoMnAl)5,即Ab5。M為(wei)稀土La、Ce、pr、Nd。
劉(liu)華福采用(yong)化(hua)學式(shi)組成為Mm0.95~1.05Ni4.08~4.40Co0.38~0.95Mn0.25~0.399Al0.32~0.49M0.04~0.999,Mm為鑭、鈰、鐠、釹的(de)(de)稀土(tu)合金,M為釩、鉍(bi)、鐵、鎵、鋅、硅、硼、鎢、鉬、鉻(ge)、鈦、鋰、錫、銅其中的(de)(de)二種(zhong)元(yuan)素(su)(su)或三種(zhong)元(yuan)素(su)(su)或四種(zhong)元(yuan)素(su)(su)。用(yong)于MH-Ni二次電(dian)(dian)池。在(zai)高溫條件下能(neng)快速充電(dian)(dian),并具有高電(dian)(dian)化(hua)學容量的(de)(de)貯氫合金材料。
李(li)蓉等人負極(ji)材料的成(cheng)分組成(cheng)(原子%)為:Ab5,組成(cheng)高溫鎳氫電池用負極(ji)材料中的,A為La、Ce、pr、Nd、Y元素(su);b為Ni、Co、Mn、Al元素(su);
四川(chuan)大(da)學(xue)已開(kai)發(fa)(fa)出性(xing)能優(you)良的(de)(de)(de)(de)(de)(de)低溫(wen)貯氫(qing)(qing)合(he)(he)金,配合(he)(he)具有特色的(de)(de)(de)(de)(de)(de)鎳(nie)氫(qing)(qing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)制(zhi)造技術,制(zhi)備出的(de)(de)(de)(de)(de)(de)額定容(rong)(rong)量(liang)(liang)8Ah的(de)(de)(de)(de)(de)(de)D型鎳(nie)氫(qing)(qing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)。該電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)經信產部天津18所、長虹電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)公司、成(cheng)(cheng)都建中鋰離子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)廠和(he)四川(chuan)大(da)學(xue)自(zi)身的(de)(de)(de)(de)(de)(de)測試(shi)發(fa)(fa)現:常溫(wen)性(xing)能為0.2C容(rong)(rong)量(liang)(liang)9.2Ah,1C容(rong)(rong)量(liang)(liang)9.0Ah,其高倍(bei)率(lv)性(xing)能約(yue)98%,小電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(0.2C~0.4C)充(chong)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)循環壽命(ming)大(da)于(yu)500次,1C大(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流充(chong)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)循環壽命(ming)大(da)于(yu)300次,常溫(wen)擱(ge)置28天的(de)(de)(de)(de)(de)(de)自(zi)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)小于(yu)10%;低溫(wen)性(xing)能為在(zai)-40℃、0.2C及(ji)-40℃、0.4C條(tiao)件下(xia)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)量(liang)(liang)達到(dao)額定容(rong)(rong)量(liang)(liang)的(de)(de)(de)(de)(de)(de)80%,在(zai)-45℃、0.2C條(tiao)件下(xia)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)量(liang)(liang)達到(dao)額定容(rong)(rong)量(liang)(liang)的(de)(de)(de)(de)(de)(de)70%;高溫(wen)性(xing)能為55℃/0.2C充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)6.5小時后(hou),0.2C放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)量(liang)(liang)大(da)于(yu)額定容(rong)(rong)量(liang)(liang)90%,55℃擱(ge)置8小時0.2C放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian),放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)量(liang)(liang)大(da)于(yu)實際(ji)容(rong)(rong)量(liang)(liang)的(de)(de)(de)(de)(de)(de)90%,50℃貯存30天容(rong)(rong)量(liang)(liang)未見(jian)任何(he)損失(shi)。在(zai)涂(tu)銘(ming)旌院士(shi)率(lv)領(ling)下(xia),之前四川(chuan)大(da)學(xue)材料學(xue)院的(de)(de)(de)(de)(de)(de)博士(shi)生導(dao)師陳云貴教(jiao)授主持完成(cheng)(cheng)了(le)無釹鎳(nie)氫(qing)(qing)動(dong)力鋰離子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)(de)開(kai)發(fa)(fa),其綜(zong)合(he)(he)性(xing)能在(zai)國(guo)內外緊要品牌(pai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)(de)對(dui)抗實驗中處于(yu)領(ling)先,獲得了(le)四項國(guo)家發(fa)(fa)明專利授權和(he)2003年(nian)我國(guo)稀土十大(da)科(ke)技新聞之一的(de)(de)(de)(de)(de)(de)榮譽。涂(tu)銘(ming)旌院士(shi)和(he)陳云貴教(jiao)授正在(zai)積極(ji)推廣此性(xing)能優(you)良的(de)(de)(de)(de)(de)(de)寬溫(wen)區鎳(nie)氫(qing)(qing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi),展開(kai)飛機(ji)用低溫(wen)大(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)性(xing)能優(you)良的(de)(de)(de)(de)(de)(de)鎳(nie)氫(qing)(qing)啟動(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)汽車用寬溫(wen)區、長壽命(ming)及(ji)低成(cheng)(cheng)本(ben)鎳(nie)氫(qing)(qing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)(de)開(kai)發(fa)(fa)[1]。
3、摻雜(za)滲鍍梯(ti)度復合球(qiu)形氫氧化鎳
球形氫氧化(hua)(hua)鎳產業(ye)化(hua)(hua)有十(shi)余年(nian)的(de)(de)(de)經(jing)歷(li),摻(chan)雜Cd+Co和(he)摻(chan)雜Zn+Co球鎳商品化(hua)(hua)比(bi)較成熟,包(bao)鈷(gu)(或(huo)稱覆鈷(gu))在逐步走向商品化(hua)(hua)。以至于有人說(shuo)[2]目(mu)前β-Ni(OH)2的(de)(de)(de)開(kai)發已(yi)接近極限;納(na)米Ni(OH)2及α-Ni(OH)2材料的(de)(de)(de)研究和(he)開(kai)發前景(jing)將會十(shi)分廣闊。
梯度功能材(cai)料(liao)(FunctionallyGradientMaterials,簡稱(cheng)FGM)是應現代工業(ye)等(deng)高技(ji)術范疇的(de)要,為滿足在極(ji)限環境(超高溫(wen)、大溫(wen)度落差)下能反復(fu)正常工作而發展起來的(de)一種新型功能材(cai)料(liao)[3]。是目前(qian)國(guo)際復(fu)合功能材(cai)料(liao)緊要發展前(qian)沿技(ji)術范疇。
摻雜滲鍍梯(ti)度(du)復合(he)球形氫氧化鎳應分為兩個概念:
一、摻雜(za)球(qiu)(qiu)形(xing)氫氧化(hua)(hua)鎳,它(ta)是(shi)在傳統的摻雜(za)Cd+Co和摻雜(za)Zn+Co球(qiu)(qiu)鎳基礎上,優化(hua)(hua)選(xuan)擇Ⅱ族(zu)元(yuan)素、稀土元(yuan)素等,制(zhi)備出成分平均(jun)、微(wei)(wei)觀結構晶粒尺寸小(xiao)、層間距大(da)、半(ban)高寬較(jiao)大(da)的摻雜(za),比表(biao)面積(ji)和粒度分布符(fu)合要求,品(pin)質穩(wen)定的球(qiu)(qiu)形(xing)氫氧化(hua)(hua)鎳。在該方(fang)面,作者認為自己開(kai)發的體系微(wei)(wei)晶在線(xian)三元(yuan)控制(zhi)法(fa),在產(chan)品(pin)穩(wen)定性(xing)、平均(jun)性(xing);工藝再線(xian)控制(zhi)簡易程度、參數精(jing)密(mi)可靠度;低廉設備投資和產(chan)品(pin)整體成本等方(fang)面處于國(guo)(guo)內領先地位。對(dui)松(song)下(xia)電(dian)池公司批量供貨(huo)一年時間、近千噸(dun)產(chan)品(pin)中,無一例品(pin)質投訴事件,開(kai)創國(guo)(guo)內同類(lei)產(chan)品(pin)之(zhi)先河[4][5]。
二、梯度(du)復(fu)合(he)(he)球(qiu)(qiu)形(xing)氫氧(yang)(yang)化(hua)(hua)(hua)鎳(nie),它與目前包(bao)鈷球(qiu)(qiu)鎳(nie)有(you)相近(jin)之處(chu),但又有(you)很大的(de)差別(bie)。包(bao)鈷球(qiu)(qiu)鎳(nie)是簡單地在(zai)球(qiu)(qiu)形(xing)氫氧(yang)(yang)化(hua)(hua)(hua)鎳(nie)中(zhong)(zhong)沉積包(bao)覆一(yi)層(ceng)(ceng)單一(yi)的(de)氫氧(yang)(yang)化(hua)(hua)(hua)鈷;梯度(du)復(fu)合(he)(he)球(qiu)(qiu)形(xing)氫氧(yang)(yang)化(hua)(hua)(hua)鎳(nie)是將欲(yu)(yu)(yu)滲(shen)材(cai)(cai)(cai)料(liao)(鈷、釔、鈦、鈣、鎂或其他稀(xi)(xi)土(tu)元(yuan)素(su)(su))與被修材(cai)(cai)(cai)料(liao)(摻(chan)雜(za)球(qiu)(qiu)鎳(nie))均(jun)放在(zai)嚴密(mi)控制(zhi)條(tiao)件的(de)狀態,滲(shen)鍍(du)離(li)子與氫氧(yang)(yang)根在(zai)添(tian)加(jia)劑(ji)的(de)用(yong)途下(xia)集(ji)中(zhong)(zhong)在(zai)基(ji)(ji)(ji)(ji)(ji)材(cai)(cai)(cai)(摻(chan)雜(za)球(qiu)(qiu)鎳(nie))表面的(de)離(li)子不斷沿著基(ji)(ji)(ji)(ji)(ji)材(cai)(cai)(cai)的(de)晶(jing)體(ti)缺陷(xian)向基(ji)(ji)(ji)(ji)(ji)體(ti)內部(bu)快速擴散(san)。最(zui)后(hou)形(xing)成(cheng)欲(yu)(yu)(yu)滲(shen)金(jin)屬(shu)元(yuan)素(su)(su)在(zai)基(ji)(ji)(ji)(ji)(ji)體(ti)表面富集(ji)結(jie)晶(jing),并滲(shen)入到基(ji)(ji)(ji)(ji)(ji)體(ti)內一(yi)定深度(du),由表及里,欲(yu)(yu)(yu)滲(shen)元(yuan)素(su)(su)濃度(du)呈(cheng)梯度(du)遞減(jian),其組織結(jie)構也(ye)呈(cheng)梯度(du)變化(hua)(hua)(hua),形(xing)成(cheng)基(ji)(ji)(ji)(ji)(ji)材(cai)(cai)(cai)外表面具有(you)欲(yu)(yu)(yu)滲(shen)金(jin)屬(shu)的(de)性(xing)能,基(ji)(ji)(ji)(ji)(ji)材(cai)(cai)(cai)心部(bu)仍(reng)保(bao)持原來的(de)性(xing)能,中(zhong)(zhong)間層(ceng)(ceng)性(xing)能逐漸過度(du)的(de)梯度(du)功(gong)能材(cai)(cai)(cai)料(liao)。組分(fen)繼續變化(hua)(hua)(hua)的(de)梯度(du)材(cai)(cai)(cai)料(liao)的(de)致密(mi)化(hua)(hua)(hua)使(shi)滲(shen)鍍(du)材(cai)(cai)(cai)料(liao)與基(ji)(ji)(ji)(ji)(ji)體(ti)結(jie)合(he)(he)牢固,制(zhi)造成(cheng)電池(chi)材(cai)(cai)(cai)料(liao)反應過程中(zhong)(zhong)滲(shen)鍍(du)材(cai)(cai)(cai)料(liao)與基(ji)(ji)(ji)(ji)(ji)體(ti)不容易脫(tuo)落,保(bao)證了電池(chi)循環性(xing)能壽命(ming)一(yi)致性(xing),通過加(jia)入選擇Ⅱ族元(yuan)素(su)(su)、稀(xi)(xi)土(tu)元(yuan)素(su)(su)等,制(zhi)備出(chu)摻(chan)雜(za)滲(shen)鍍(du)梯度(du)復(fu)合(he)(he)球(qiu)(qiu)形(xing)氫氧(yang)(yang)化(hua)(hua)(hua)鎳(nie)從而獲得高溫(wen)鎳(nie)氫電池(chi)的(de)效(xiao)果。
4、結論
在鎳(nie)氫(qing)電池(chi)正極配(pei)料中添(tian)加稀土、稀有、堿土元素或氧化(hua)(hua)(hua)物(wu),能改善鎳(nie)氫(qing)電池(chi)在高溫狀態性能,其(qi)中具有代(dai)表性的元素為:如Mg、Ca、Sr、Sc、Y、La、鑭系元素、Ti、Zr、Cr、Mo、W、Mn、Fe、Co、Cu、Zn、Cd、b、Al、Ga、In、Si、p、As、Sb、bi其(qi)中一種或多種氧化(hua)(hua)(hua)物(wu)、氫(qing)氧化(hua)(hua)(hua)物(wu)。其(qi)中鋯(gao)在新能源材(cai)料中研究使用(yong)有不少解(jie)析(xi)[6][7][8],除鋯(gao)在(核能,鋯(gao)板、管(guan)材(cai))有產(chan)業(ye)化(hua)(hua)(hua)實(shi)際(ji)使用(yong)之(zhi)外,其(qi)他在鎳(nie)氫(qing)正負極材(cai)料和鋰離子電池(chi)正極材(cai)料添(tian)加劑中尚(shang)不具備產(chan)業(ye)化(hua)(hua)(hua)的實(shi)際(ji)使用(yong)。機(ji)械(xie)混(hun)合(he)法(fa)表面混(hun)合(he)存在平均(jun)性問題從而影響性能;化(hua)(hua)(hua)學沉淀(dian)摻雜(za)、包覆較機(ji)械(xie)混(hun)合(he)法(fa)有一定(ding)優點(dian),仍存在加工工藝(yi)控制的技術;摻雜(za)滲鍍梯度復合(he)球形(xing)氫(qing)氧化(hua)(hua)(hua)鎳(nie)可能是處理上述缺陷的有效方法(fa)。

 




