'O ka mana'o o ka lithium-ion electrolyte?

◆He aha nā mea electrolytes wai?

◆Hoʻolauna i nā Electrolytes Solid

ʻO ka electrolyte, kahi mea pono ʻole onā ʻakika lithium -ion, he kuleana ko'iko'i 'o ia i ka ho'oku'u 'ana o ka 'akika -cycles.

ʻAʻole wale ia ke kuleana no ka lawe pono ʻana o nā ion lithium a me ka hoʻokele o kēia manawa, akā loaʻa pū kekahi mau waiwai insulation uila e pale pono ai i ke kahe electron pololei ma waena o nā electrodes maikaʻi a maikaʻi ʻole. Ma ke ʻano kiʻi, ua like ka electrolyte me ke "koko" i loko o kahi pākaukau lithium-ion, e hōʻoia ana i ka pilina ma waena o nā mea electrode maikaʻi a me ka ʻinoʻole, a laila e hōʻoiaʻiʻo ai i ka holomua o ke kaʻina hoʻoiho holoʻokoʻa.

Pono ka electrolyte kūpono no ka pākaukau lithium-ion i nā koi ʻelima:

Me ka pi'i 'ana o nā koi no ka nui o ka ikehu pilahi a me ka nui o ka mana, e ulu wikiwiki ana ka 'enehana pila, a ua holomua nui na mea electrode. I ka hoʻohālikelike ʻana, ua lohi ka hoʻomohala ʻana o nā ʻōnaehana electrolyte. I kēia manawa, hiki ke ho'oka'awale 'ia ka ho'omohala 'ana o nā pā uila lithium-ion i 'ekolu 'ano: non-aqueous solvent electrolytes, aqueous electrolytes, and solid{5}}state electrolytes.

ʻAʻohe-mea hoʻoheheʻe wai electrolyte

 

ʻAʻole-aqueous solvent electrolytes in lithium-ion batteries e pili ana i nā ʻōnaehana electrolyte ʻaʻohe wai, i haku ʻia me nā solvents, solutes (maʻa mau nā paʻakai lithium), a me nā mea hoʻohui. ʻO kēia mau mea hoʻoheheʻe wai ʻole he mau mea hoʻoheheʻe maʻamau, ma mua o nā mea hoʻoheheʻe wai, e pale i ka electrolysis o ka wai a i ʻole nā ​​hopena ʻino me nā mea electrode. ʻO nā paʻakai Lithium nā mea lawe mua no ka lawe ʻana i ka lithium -ion, nā mea hoʻoheheʻe ka mea hoʻoheheʻe, hoʻopuehu, a me ke kākoʻo ʻana i nā paʻakai lithium, a me nā mea hoʻohui e hoʻomaikaʻi i ka hana electrochemical a i ʻole ka palekana o nā pākahi lithium-ion.

ʻO nā electrolytes i loaʻa ma ke kūʻai aku (ʻo ia hoʻi, nā wai electrolytes) i hoʻohana ʻia i loko o nā pākahi lithium -ion i haku mua ʻia me hoʻokahi a ʻoi aku paha nā paʻakai lithium i hoʻoheheʻe ʻia i loko o ʻelua a ʻoi aʻe nā mea hoʻoheheʻe organik; kakaʻikahi loa nā electrolytes i haku ʻia me hoʻokahi solvent. ʻO ke kumu o ka hoʻohana ʻana i nā mea hoʻoheheʻe he nui, ʻo ia ka -ʻano ʻē aʻe o nā ʻokoʻa ʻokoʻa o ka honua maoli, ʻokoʻa paha nā koi i paʻakikī ke hoʻokō me ka hoʻohana ʻana i hoʻokahi solvent. No ka laʻana, pono nā electrolytes i ka wai kiʻekiʻe me ka loaʻa ʻana o ka dielectric kiʻekiʻe; No laila, hoʻohana pinepine ʻia nā mea hoʻoheheʻe me nā ʻano physicochemical like ʻole i ka hui pū ʻana, e hōʻike ana i nā ʻano like ʻole i ka manawa like. Eia kekahi, ʻaʻole hoʻohana ʻia nā paʻakai lithium i ka manawa like no ka mea ua kaupalena ke koho ʻana i nā paʻakai lithium, a ʻaʻole maʻalahi ko lākou mau pono.

Pono e loaʻa i nā mea hoʻoheheʻe kūlohelohe kūpono kēia mau waiwai nui: ʻO ka mea mua, pono lākou i kahi mau dielectric kiʻekiʻe e hōʻoia i ka hoʻoheheʻe maikaʻi ʻana o nā paʻakai lithium; ʻO ka lua, pono lākou he wahi hoʻoheheʻe haʻahaʻa a me kahi kiʻekiʻe e hoʻolapalapa ai e hoʻonui i ka pae wela hana o ka electrolyte; ʻO ke kolu, ʻo ka haʻahaʻa haʻahaʻa e kōkua i ka hoʻoikaika ʻana i ka neʻe maikaʻi ʻana o nā ion lithium i ka waena; a ʻo ka mea hope loa, pono ke kūʻai ʻia kēia mau mea hoʻoheheʻe a haʻahaʻa ka ʻona (ʻoi loa ʻaʻole -ʻona). ʻO nā pūhui kalapona, ʻo ia kekahi o nā mea hoʻoheheʻe kūlohelohe mua loa a hoʻohana nui ʻia i ka ʻoihana pākaukau lithium-ion, he kūlana koʻikoʻi ma ke kahua o nā electrolytes pākaukau.

I kēia manawa, loaʻa i kēia ʻano solvent ʻelua mau ʻano hana: cyclic a me ke kaulahao. Hōʻuluʻulu ka papa ma lalo nei i nā ʻāpana kino kūpono o kekahi mau mea hoʻoheheʻe wai ʻole, electrolytes, a me nā mea hoʻoheheʻe kūlohelohe.

I kēia manawa, hoʻohana nui ʻia nā solvents alkyl carbonate i nā electrolytes. Loaʻa i kēia mau mea hoʻoheheʻe ke kūpaʻa oxidation maikaʻi a hōʻike i ke kūpaʻa maikaʻi loa ma lalo o nā kūlana uila kiʻekiʻe. ʻO nā carbonate cyclic, e like me ka ethylene carbonate a me ka propylene carbonate, ua ʻike ʻia no ko lākou mau dielectric kiʻekiʻe, ʻo ia hoʻi hiki iā lākou ke hoʻoheheʻe i nā paʻakai lithium me ka maikaʻi loa; akā naʻe, ma muli o nā ikaika intermolecular ikaika, ua loaʻa i kēia mau solvents ka viscosity kiʻekiʻe, e hoʻolohi i ka neʻe ʻana o nā ion lithium i loko o lākou. I ka hoʻokaʻawale ʻana, ʻo nā kaulahao carbonates, e like me ka dimethyl carbonate a me diethyl carbonate, ʻoiai he haʻahaʻa ka viscosity, he haʻahaʻa haʻahaʻa hoʻi nā dielectric mau, e hopena i ka maikaʻi ʻole o ka hoʻoheheʻe ʻana no nā paʻakai lithium. No laila, no ka hoʻomākaukau ʻana i nā ʻōnaehana hoʻonā me ka conductivity ionic kiʻekiʻe, hui pinepine ʻia nā ʻano solvents, e like me nā hui PC + DEC a i ʻole EC + DMC. ʻO nā paʻakai lithium, ʻo ia ke kumu o nā ion lithium i loko o ka electrolyte, ke pāʻani nui nei i ka lawe ʻana i ka ion lithium -iona i ka wā o ka hoʻouka ʻana a me ka hoʻokuʻu ʻana o nā ʻona lithium-ion. Hoʻopili pololei kā lākou hana i nā ʻano he nui o nā ʻakika lithium{10}}ion, e like me ka nui o ka ikehu, ka nui o ka mana, ka nui o ka uila hana, ke ola pōʻai, a me ka palekana. I kēia manawa, ma ka ʻimi noiʻi a me ka hana ʻenehana, koho maʻamau nā paʻakai lithium me ka radii anionic nui a me ke kūpaʻa redox kiʻekiʻe. Ma muli o kā lākou hana kemika, hiki ke hoʻokaʻawale ʻia nā paʻakai lithium i ʻelua mau ʻāpana: nā paʻakai lithium inorganic a me nā paʻakai lithium organik. Ua kūkulu ʻia kekahi mau paʻakai lithium inorganic, me LiPF6, LiClO4, LIBF, a me LIASF. ʻO ka mea like ʻole, hoʻohana ʻia nā paʻakai lithium organik i hoʻohana mau ʻia i loko o nā pākahi lithium{17}}ion ma o ka hoʻohui ʻana i nā pūʻulu wehe electron i nā anion o kēia mau paʻakai lithium inorganic, e like me ka lithium dioxalato-borate (LiBOB), lithium difluorooxalato-litium (LiFluoroBrate]),[ilimide di-fluoroborate (LiFluoroB) lithium ditrifluoromethylsulfonylimide (LTFSI). Hōʻike ka papa ma lalo nei i nā waiwai physicochemical kūpono o kekahi mau paʻakai lithium i hoʻohana mau ʻia i loko o nā pākahi lithium-ion.

ʻO nā mea hoʻohui he mau mea i hoʻohui ʻia i ka electrolyte ma nā haʻahaʻa haʻahaʻa (maʻamau ʻaʻole i ʻoi aku ma mua o 10% e ka nuipa) i loaʻa nā hana kikoʻī a hiki ke hoʻomaikaʻi nui i nā ʻano electrochemical o ka pā. Ma muli o kā lākou mau hana, hiki ke hoʻokaʻawale ʻia kēia mau mea hoʻohui i nā ʻāpana he nui: -mea hoʻohui kiʻiʻoniʻoni, pale ahi, a me nā mea hoʻohui e pale ai i ka hoʻonui ʻana. Eia hou, aia nā mea hoʻohui i hoʻohana ʻia no ka hoʻoikaika ʻana i ka conductivity, ka hoʻokō ʻana i ka hana ma lalo o -ʻano wela haʻahaʻa, a i ʻole ka hoʻomalu ʻana i ka nui o nā meheu a me ka HF i loko o ka solution electrolyte.