3 3 1997 8 EL ECTROCH EM ISTR Y V o l 3 N o 3 A ug 1997 3 ( 300071) ( ) ; ( ) (- 1 1-0 4 V ) (- 1 1-0 2 V ) Cu2O 2 (KOH ) Cu 2 g (N igm H ) [ 1 3 Cd ] AB 5 N i [ 4 ] Cu [ 5 ] ( N i2h ) T Sakai [ 6 ] 20% X Cu2O 2 (KOH ) Cu 2 1997201215 1997206210
264 1997 1 1 1 TD 3690 V ectra 286g12 H go gh g KOH ( ) 1 2 M LN i3 8Co 0 5M n0 4A l0 3 ( ) 3002400 0 15 m o lgl HC l C l - Cu 2+ + 2HCHO + 4OH - Cu 0 + H 2 + 2H 2O + 2HCOO - ( 50 g 10% ) 1) 25 g CuSO 4 5H 2O 60 g ED TAN a2 2H 2O 15 g N aoh 300 m l ; 2) ; 3) 65 4502470 rgm in 20 m l 65 m l 5 m o lgl 1 3 (M LN i3 8Co 0 5M n 0 4A l0 3-10% Cu) 0 15 g 2% PVA 1 0 1 0 cm 2 20 m pa ( 99 5% 100-200 ) 0 12 mm 1 cm 1 cm 1 4 D gm ax2χa x (CuK Α ) PER K IN ELM ER PH 15300 ESCA X X M gk a 10-9 To rr A r + 10 nm gm in A po llo 1 5 5 m o lgl KOH H go gh g 25 TD 3 690 5 0 2 C - 0 15 V
3 : 265 : - 0 15 V (vs H go gh g) : 10 s : - 0 70 V (vs H go gh g) : 120 s 2 2 1 XRD ( 1a) CaCu 5 2 Η 43 3 50 4 74 0 ( 1b) 2 2 (XPS) 2 XPS Cu O C C : 1) ; 2) 1 X a) ; 3) b) ( 2) Cu 2p 3g2 F ig 1 X2ray diffraction of the hydrogen sto rage alloy 932 5 ev a) uncoated b) 10% Cu2coated ; 934 5 ev Cu CuO 200 1 C (100%DOD ) 70% A r + 10 m in 27% XPS ( 3) ; A r + 5 m in 2 XPS a) b) F ig 2 a) XPS spectra from the copper2coated surfaces b) XPS spectra of the Cu 2p 3g2 peak
266 1997 2 3 ( ) 4-0 3 V - 0 6 V 3 200 1 C (100%DOD ) (a) (b)a r + 5 J S H alliday m in F ig 3 XPS spectra of copper from the copper2coated hydrogen [ 7 10 ] sto rage alloy sufraces after 200 charging2discharging cy2 cles (100% DOD ) OH - (a) as coated (b) sputtered fo r 5 m in 2 2Cu+ 2OH 2 [ Cu2O + H 2O + 2e 2 (1) Cu2O + 2OH 2 [ 2CuO + H 2O + 2e 2 (2) 5 4 m o lgl KOH : a) - 1 1 V - 0 4 V ; b) - 1 1 V - 0 2 V 5 (v = 2 mv s - 1 T = 25 0 0 1 ) F ig 4 V o ltammogramm s obtained on the copper2coated hydrogen sto rage alloy electrode (a) scanning betw een - 1 1 V and - 0 4 V W akkad [ 10 ] (b) scanning betw een - 1 1 V and - 0 2 V H ick ling T aylo r [ 9 ] [ 11 g 2g g 2g ] g g H alli2 day - 1 1 V
3 : 267 g 2g Cu2O + 6OH - 2 2 + 3H 2O + 2e - (3) 4-0 3 V - 0 6 V 5 CugCu2O (v = 10 mv s - 1 T = 25 0 0 1 ) F ig 5 V o ltammogram obtained on copper electrode EC Y R R [ O + ne - M H abs M H ads (4) M H ads+ OH - [ M + H 2O + e - (5) EC H 2O OH - (10-5 10-7 cm 2 gs) [ 12 ] ( 10-10 cm 2 gs ) [ 13 ] 2 4 Cu2O 2 KOH Cu ( ) 2 2
268 1997 2 2 + 2H 2O + 2e - [ Cu+ 4OH - (6) 2 6 1) 6 CuO - 2 2 ( ) a) b) c) F ig 6 Po tential2step curves fo r 2 on nickel electrode (th ree tim es on the sam e substrate a) first tim e; b) 2) second tim e and c) th ird tim e) i t i t 2 ( ) i t 3 ( ) 3) [ 14 ] t> tm ( tm 7 i 2 gi m tgtm ) 2 a) ; b) ; c) F ig 7 D im ensionless curves of i 2 gi m 2 vṡ tgtm fo r the CuO - 2 2 electrodepo sited on n ickel electrode a) theo retical in stan taneou s nucleation; b ) theo reti2 cal p rogressive nucleation; c ) experim en tal nucle2 ln ( ig ation t) t 2 i t 2
3 : 269 [ 15 ] F leischm ann i = (2nF ΠM N ok 2 tgθ) exp (2ΠM 2 N ok 2 t 2 gθ 2 ) ( ) i = (nf ΠM N obk 2 h t 2 gθ) exp (2ΠM 2 N obk 2 t 3 g3θ 2 ) ( ) N o t> 0 K h ( ) Θ M i 2 gi 2 m tgtm 7 ( 6 a) i 2 gi 2 m tgtm ( 7 c) 2 7 [ 16 ] 2 [ 15 ( ) ] : i= 2ΠnN of K 2 hm tgθ i t [ 15 (im tm ) ] : i= (2nF ΠM N ok 2 h tgθ) exp - ΠM 2 N ok 2 t 2 gθ 2 ln (igt) t 2 3 1) XPS 2) 3) 2 Behavio r of Copper in H ydrogen Sto rage A lloy M icroencap su lated by Copper Zhang D aw ei 3 Yuan H uatang Yang H uab in Zhou Zuox iang Zhang Yun sh i (Insṫ of N ew E nergy M a teria l Chem N anka i U n iv T ianj in 300071) A bs tra c t N egative electrode m ade from Cu2m icroencap su lated hydrogen sto rage al2 loy w as studied by u sing cyclic vo ltamm etry m ethod T he resu lts show ed that copper as a coat2 ing m aterial w as of a certain stab ility in 5 m o lgl KOH so lu tion w ith in the range of charge and discharge vo ltage But w hen expanding the sw eep vo ltage the CV cu rve show ed a pair of dis2
270 1997 tinct ox idation2reduction cu rren t peak s of Cu2O fo rm ation at E = - 0 3 V and Cu2O reduction at E = - 0 6 V W ith charging2discharging cycles copper is liab le to be ox idized to Cu2O and fu rther ox idized in to 2 W hen charged again 2 an ion is reduced and Cu is electrode2 po sited on the sufrace of electroce In respond to th is phenom enon the electrodepo sition p ro2 cess of 2 on the sm oo th N i electrode w as studied by con stan t po ten tial step techn ique resu lts show ed that the depo sition p rocess of copper fo llow ed the tw o2dim en sion in stan taneou s m echan ism Ke y w o rds H ydrogen sto rage alloy M icroencap su lation Copper Cyclic vo ltam 2 m etry Con stan t po ten tial step techn ique E lectrodepo sition T he Re fe re nce s 1 : 1990 2 : 1984 3 Furukaw a N D evelopm ent and comm ercialization of nickel2m etal hydride secondary batterieṡ J of P ow er S ou rces 1994 51: 45 59 4 Chen Jun Zhang Yunsh i N ickelgm etal hydride batteries using m icroencap sulated hydrogen sto rage alloy Inṫ J H y d rog en E nergy 1995 20(3): 235 237 5 Sakai T Ish ikaw a H O guro K et al Effects of m icroencap sulation of hydrogen sto rage alloy on the perfo r2 m ances of sealed nickelgm etal hydride batterieṡ I E lectrochem S oc 1987 134: 558 562 6 Sakai T Yuasa A Ish ikaw a H et al N ickel2m etal hydride battery using m icrom cap sulated alloyṡ J L ess2 Comm on M eṫ 911 172 174: 1 194 1 204 7 H alliday J S T he anodic behaviour of copper in acustic soda so lutionṡ T rans F arad ay S oc 1962 50: 171 178 8 K im C P N obe Ken Po larization of copper in acidic and alkaline so lutionṡ Corrosion 1971 27(9): 382 385 9 H ick ling A T aylo r D T he anodic behaviour of m etalṡ part V 2coppeṙ T rans F arad ay S oc 1948 44: 262 268 10 W akkad S E S Em era S H T he anodic oxidation of m etals at very low current density part g 3 coppeṙ J Chem S oc 1953 12: 3 508 3 512 11 : 1984 12 : 1987 13 Sch lapbach L H ydrogen in interm etallic compounds(g ) Sp ringer2v erlag 1992 14 A rm strong R D M etcalfe A A Tw o dim ensional nucleation and grow th - T he po tentio static case J E lectroanal Chem 1975 63: 19 22 15 F leischm ann M T h irst H R A dvan E lectrochem E lectrochem Eng V o l 3 (Ed by D alahay P) N ew Yo rk: W iley 1963: 123 16 T rejo G Gil A F Gonzalez İ E lectrodepo sition of go ld in ammoniacalm edium: influence of substrate and temperature J A pp lied E lectrochem 1996 26: 1 287 1 294