1. Introduction to Lithium Ion Battery

1.1 Jiha-Na-Caji (SOC)

Ana iya bayyana yanayin caji azaman yanayin samar da wutar lantarki a cikin baturi, yawanci ana bayyana shi azaman kashi. Domin samar da makamashin lantarki ya bambanta da caji da fitarwa na yanzu, zafin jiki, da al’amuran tsufa, ma’anar yanayin cajin kuma an kasu kashi biyu: Cikakkar Jiha-Of-Caji (ASOC) da Ƙasar-Cikin Dangi (Jahar dangi). -Na-Caji; ASOC) Jihar-Na-Cajin; RSOC). Yawanci yanayin yanayin cajin shine 0% -100%, yayin da baturin shine 100% lokacin da aka cika cikakken caji da 0% idan an cika cikakke. Cikakken yanayin caji shine ƙimar tunani da aka lasafta bisa ga ƙayyadaddun ƙimar ƙarfin da aka ƙera lokacin da aka kera baturi. Cikakken yanayin cajin sabon baturi mai cikakken caji shine 100%; kuma ko da batirin tsufa ya cika cikakke, ba zai iya kaiwa 100% ƙarƙashin yanayin caji da caji daban-daban.

Hoton da ke ƙasa yana nuna alaƙar ƙarfin lantarki da ƙarfin baturi a ƙimar fitarwa daban-daban. Mafi girman adadin fitarwa, ƙananan ƙarfin baturi. Lokacin da zafin jiki yayi ƙasa, ƙarfin baturi shima zai ragu.

Hoto 1.

Dangantaka tsakanin ƙarfin lantarki da ƙarfi a ƙimar fitarwa daban-daban da yanayin zafi

1.2 Max Charging Voltage

The maximum charging voltage is related to the chemical composition and characteristics of the battery. The charging voltage of lithium battery is usually 4.2V and 4.35V, and the voltage value will be different if the cathode and anode materials are different.

1.3 Cikakken Cajin

Lokacin da bambanci tsakanin ƙarfin baturi da mafi girman ƙarfin caji bai wuce 100mV ba, kuma cajin halin yanzu ya ragu zuwa C/10, ana iya ɗaukar baturin a matsayin cikakken caji. Halayen baturi sun bambanta, kuma cikakkun yanayin cajin ma sun bambanta.

Hoton da ke ƙasa yana nuna nau’in cajin baturin lithium na yau da kullun. Lokacin da ƙarfin baturi yayi daidai da mafi girman ƙarfin caji kuma cajin halin yanzu ya ragu zuwa C/10, ana ɗaukar baturin cikakken caji.

Hoto 2. Siffar lanƙwasa tana cajin baturin lithium

1.4 Karamin Fitar da Wutar Lantarki

The minimum discharge voltage can be defined by the cut-off discharge voltage, which is usually the voltage when the state of charge is 0%. This voltage value is not a fixed value, but changes with load, temperature, aging degree, or other factors.

1.5 Cikakkun Ciki

Lokacin da ƙarfin baturi ya yi ƙasa da ko daidai da mafi ƙarancin ƙarfin fitarwa, ana iya kiransa cikakken fitarwa.

1.6 Yawan caji da fitarwa (C-Rate)

Matsakaicin caje-jini magana ce ta fitar da caji na halin yanzu dangane da ƙarfin baturi. Misali, idan aka yi amfani da 1C don fitarwa na awa daya, da kyau, batirin zai cika gaba daya. Caji daban-daban da ƙimar fitarwa za su haifar da ƙarfin amfani daban-daban. Gabaɗaya, mafi girman ƙimar cajin, ƙarancin ƙarfin da ake samu.

1.7 Rayuwar zagayowar

Adadin zagayowar shine adadin lokutan da baturi ya yi cikakken caji da fitarwa, wanda za’a iya ƙididdige shi daga ainihin ƙarfin fitarwa da ƙarfin ƙira. Duk lokacin da ƙarfin fitarwa da aka tara yayi daidai da ƙarfin ƙira, adadin zagayowar sau ɗaya ne. Yawancin lokaci bayan zagayowar caji 500, ƙarfin cikakken cajin baturi yana raguwa da 10% ~ 20%.

Figure 3. The relationship between the number of cycles and battery capacity

1.8 Fitar da Kai

Fitar da kai na duk batura yana ƙaruwa yayin da zafin jiki ya tashi. Fitar da kai a zahiri ba lahani bane na masana’anta, amma halayen baturin kanta. Koyaya, rashin kulawa a cikin tsarin masana’anta kuma na iya haifar da haɓakar fitar da kai. Gabaɗaya, ƙimar fitar da kai yana ninka sau biyu akan kowane karuwar 10°C na zafin baturi. Fitar da kai na batirin lithium-ion kowane wata shine kusan 1 ~ 2%, yayin da fitar da kai kowane wata na batura masu tushen nickel daban-daban shine 10-15%.

Hoto 4. Ayyukan aikin fitar da kai na batir lithium a yanayin zafi daban-daban

2. Gabatarwa ga Ma’aunin Fuel Baturi

2.1 Gabatarwa zuwa Ayyukan Ma’aunin Man Fetur

Ana iya ɗaukar sarrafa batir azaman ɓangare na sarrafa wutar lantarki. A cikin sarrafa baturi, ma’aunin mai yana da alhakin kimanta ƙarfin baturi. Asalin aikinsa shine kula da wutar lantarki, caji/fiddawar halin yanzu da zafin baturi, da kimanta yanayin cajin baturi (SOC) da ƙarfin cajin baturi (FCC). Akwai hanyoyi guda biyu na yau da kullun don kimanta yanayin cajin baturi: Hanyar wutar lantarki ta buɗe (OCV) da hanyar coulometric. Wata hanyar ita ce tsayayyen ƙarfin lantarki algorithm wanda RICHTEK ya tsara.

2.2 Buɗe hanyar wutar lantarki

Mitar wutar lantarki ta amfani da hanyar wutar lantarki ta buɗewa ya fi sauƙi don aiwatarwa, kuma ana iya samun ta ta hanyar duba tebur ɗin da ya dace da yanayin cajin wutar lantarki na buɗewa. Yanayin hasashe na buɗaɗɗen wutar lantarki shine ƙarfin ƙarfin baturi lokacin da baturin ya tsaya na kusan mintuna 30.

Ƙarƙashin nauyi daban-daban, zafin jiki, da tsufa na baturi, madaurin ƙarfin baturi zai bambanta. Saboda haka, ƙayyadadden voltmeter mai buɗewa ba zai iya wakiltar yanayin caji gabaɗaya ba; Ba za a iya kimanta yanayin cajin ta hanyar kallon tebur kadai ba. A wasu kalmomi, idan an kiyasta yanayin cajin kawai ta hanyar duba tebur, kuskuren zai yi girma sosai.

Wannan adadi na gaba ya nuna cewa irin ƙarfin lantarkin baturi ɗaya yana ƙarƙashin caji da fitarwa, kuma yanayin cajin da aka samu ta hanyar buɗaɗɗen wutar lantarki ya bambanta sosai.

Hoto 5. Wutar lantarki a ƙarƙashin caji da fitarwa

Hoton da ke ƙasa yana nuna cewa yanayin cajin ya bambanta sosai a ƙarƙashin kaya daban-daban yayin fitarwa. Don haka a zahiri, hanyar buɗe wutar da’ira ta dace da tsarin da ƙananan buƙatu don daidaiton yanayin caji, kamar yin amfani da batir-acid-acid ko samar da wutar lantarki mara yankewa a cikin motoci.

Hoto 6. Wutar lantarki a ƙarƙashin kaya daban-daban yayin fitarwa

2.3 Hanyar aunawa Coulomb

Ka’idar aiki ta hanyar auna coulomb ita ce haɗa resistor mai ganowa akan hanyar caji/cajin baturi. ADC tana auna ƙarfin lantarki akan resistor ɗin ganowa kuma yana canza shi zuwa ƙimar halin yanzu na baturin da ake caji ko fitarwa. Ma’aunin lokaci na ainihi (RTC) yana ba da haɗin kai na halin yanzu tare da lokaci, don sanin yawan coulombs da ke gudana.

Hoto 7. Hanyar aiki na asali na hanyar ma’aunin Coulomb

Hanyar aunawa ta Coulomb na iya ƙididdige ainihin lokacin caji yayin caji ko fitarwa. Tare da ma’aunin cajin coulomb da counter coulomb na fitarwa, zai iya ƙididdige ƙarfin da ya rage (RM) da cikakken ƙarfin caji (FCC). Hakanan ana iya amfani da ragowar ƙarfin (RM) da cikakken caji (FCC) don ƙididdige yanayin cajin, wato (SOC = RM/FCC). Bugu da ƙari, yana iya ƙididdige lokacin da ya rage, kamar ƙarancin wutar lantarki (TTE) da cikakken iko (TTF).

Figure 8. Calculation formula of Coulomb measurement method

Akwai manyan abubuwa guda biyu waɗanda ke haifar da sabani a cikin daidaiton hanyar ma’aunin Coulomb. Na farko shine tarin kurakurai a cikin ji na yanzu da ma’aunin ADC. Kodayake kuskuren ma’auni tare da fasaha na yanzu yana da ƙananan, idan babu wata hanya mai kyau don kawar da shi, kuskuren zai karu da lokaci. Hoton da ke ƙasa yana nuna cewa a cikin aikace-aikace masu amfani, idan babu gyara a cikin tsawon lokaci, kuskuren da aka tara ba shi da iyaka.

Hoto 9. Kuskuren tarawa na hanyar ma’aunin Coulomb

In order to eliminate the accumulated error, there are three possible useable time points in normal battery operation: end of charge (EOC), end of discharge (EOD) and rest (Relax). When the charging end condition is reached, it means that the battery is fully charged and the state of charge (SOC) should be 100%. The discharge end condition means that the battery has been completely discharged and the state of charge (SOC) should be 0%; it can be an absolute voltage value or change with the load. When it reaches the resting state, the battery is neither charged nor discharged, and it remains in this state for a long time. If the user wants to use the rest state of the battery to correct the error of the coulomb measurement method, an open-circuit voltmeter must be used at this time. The figure below shows that the state of charge error can be corrected in the above state.

Hoto 10. Sharuɗɗan don kawar da kuskuren tarawa na hanyar ma’aunin Coulomb

Babban abu na biyu da ke haifar da karkatar da daidaiton hanyar auna coulomb shine kuskuren cikakken caji (FCC), wanda shine bambanci tsakanin ƙimar ƙarfin ƙirar baturi da ainihin cikakken ƙarfin cajin baturi. Cikakkun ƙarfin caji (FCC) zafin jiki, tsufa, nauyi da sauran abubuwan zai shafi su. Sabili da haka, hanyar sake koyo da ramuwa na cikakken ƙarfin caji yana da mahimmanci ga hanyar ma’aunin coulomb. Hoto mai zuwa yana nuna yanayin yanayin kuskuren caji lokacin da aka ƙima da cikakken ƙarfin cajin da rashin ƙima.

Hoto 11. Kuskuren kuskure lokacin da cikakken ƙarfin cajin ya wuce kima da ƙima

2.4 Dynamic ƙarfin lantarki algorithm ma’aunin man fetur

Ma’aunin wutar lantarki mai ƙarfi algorithm na man fetur na iya ƙididdige yanayin cajin baturin lithium bisa ƙarfin ƙarfin baturi kawai. Wannan hanyar ita ce kimanta haɓaka ko raguwar yanayin caji bisa ga bambanci tsakanin ƙarfin baturi da buɗaɗɗen wutar lantarki na baturi. Bayanin ƙarfin lantarki mai ƙarfi na iya daidaita halayen baturin lithium yadda ya kamata don tantance yanayin cajin SOC (%), amma wannan hanyar ba zata iya ƙididdige ƙimar ƙarfin baturi (mAh).

Hanyar lissafinsa ta dogara ne akan bambancin ƙarfin baturi da ƙarfin lantarki na buɗewa, ta hanyar amfani da algorithm na jujjuya don ƙididdige kowane karuwa ko raguwa na yanayin caji don kimanta yanayin caji. Idan aka kwatanta da maganin ma’aunin ma’aunin man fetur na coulomb, ma’aunin wutar lantarki mai ƙarfi algorithm ma’aunin man fetur ba zai tara kurakurai akan lokaci da na yanzu ba. Ma’aunin ma’aunin mai na Coulomb yawanci yana haifar da ƙima mara kyau na yanayin caji saboda kurakuran ji na yanzu da fitar da batir da kansa. Ko da kuskuren ji na yanzu yana da ƙanƙanta, ma’aunin coulomb zai ci gaba da tara kuskuren, kuma kuskuren da aka tara za a iya kawar da shi ne kawai lokacin da aka cika caji ko kuma ya cika.

Ma’aunin wutar lantarki mai ƙarfi algorithm ma’aunin man fetur yana ƙididdige yanayin cajin baturin kawai ta bayanin ƙarfin lantarki; saboda ba a ƙididdige shi da bayanan baturi na yanzu, ba ya tara kurakurai. Domin inganta daidaiton yanayin caji, ƙarfin ƙarfin lantarki algorithm yana buƙatar amfani da ainihin na’ura, da daidaita ma’auni na ingantaccen algorithm bisa ga ainihin ma’aunin ƙarfin baturi lokacin da ya cika caja da cikar fitarwa.

Hoto 12. Ayyukan ƙarfin ƙarfin lantarki mai ƙarfi algorithm ma’aunin man fetur da samun haɓakawa

Mai zuwa shine aikin algorithm mai ƙarfi mai ƙarfi a ƙarƙashin yanayin ƙimar fitarwa daban-daban. Ana iya gani daga adadi cewa yanayin cajinsa yana da daidaito mai kyau. Ko da kuwa yanayin fitarwa na C/2, C/4, C/7 da C/10, gaba ɗaya kuskuren cajin wannan hanyar bai wuce 3%.

Hoto 13. Ayyukan yanayin cajin algorithm mai ƙarfi mai ƙarfi a ƙarƙashin yanayin ƙimar fitarwa daban-daban

Hoton da ke ƙasa yana nuna aikin yanayin caji lokacin da baturin yayi gajeriyar caji da gajeriyar fitarwa. Kuskuren caji har yanzu yana da ƙanƙanta, kuma mafi girman kuskuren shine kawai 3%.

Hoto 14. Ayyukan yanayin cajin algorithm mai ƙarfin lantarki lokacin da baturi ya kasance ɗan gajeren caji da gajeriyar fitarwa.

Idan aka kwatanta da halin da ake ciki inda ma’aunin ma’aunin man fetur na Coulomb yakan haifar da yanayin caji mara kyau saboda kurakuran ji na yau da kullun da fitar da batir, algorithm mai ƙarfi ba ya tara kurakurai akan lokaci da na yanzu, wanda shine babban fa’ida. Saboda babu wani bayani game da caji/fitarwa na yanzu, ƙarfin ƙarfin lantarki algorithm yana da ƙarancin ɗan gajeren lokaci da jinkirin amsawa. Bugu da ƙari, ba zai iya ƙididdige cikakken ƙarfin caji ba. Koyaya, yana aiki da kyau dangane da daidaito na dogon lokaci, saboda ƙarfin baturi zai nuna yanayin cajin sa kai tsaye.