Wanem samting em LiFePO4 insait long ol litiam bateri??
Introdaksen long ol samting bilong litiam ain fosfet
Litiam ain fosfet (molekula fomula LiFePO₄, litiam ain fosfet, LFP, ol i save kolim tu olsem litiam ain fosfet o feros litiam fosfet) em i wanpela katod samting we ol i save yusim long ol litiam-ion bateri. Ol samting bilong en em olsem em i no gat ol gutpela samting olsem kobalt o nikel, prais bilong ol samting bilong wokim em i liklik; na kabon, litiam, na ain i planti tru insait long graun, na dispela inap long inapim laik bilong maket long winim wan milion ton long olgeta yia. Olsem wanpela 'cathode material', 'lithium iron phosphate' i gat liklik wok voltej (3.2 V), bikpela spesifik kapasiti (170 mA·h/g), bikpela 'discharge power', 'fast charging capability', na longpela saikel laip, wantaim gutpela stebiliti long bikpela-temperature na bikpela-hat envairomen.
Lithium iron phosphate crystal em i bilong wanpela kain olivin straksa. Insait long mineralogi, ol i kolim em 'triphylite', we i kam long tok Grik 'tri' na 'lylon'. Insait long ol ston, kala bilong en i ken i stap grei, retpela-braun grei, braun, o blak, tasol ol prodak tru em i blak o grei-blak. Sampela mineral samting i gat 'lithium iron phosphate', tasol mak bilong en i liklik na i no inap long yusim. Lithium iron phosphate em i bilong 'composite phosphate' kategori, na jenerel kemikel fomula bilong en i mas LiMPO4, we M i ken kamap olsem wanem kain divalen metal, olsem Fe, Co, Mn, Ti, na ol narapela. Bikos namba wan kampani long salim LiMPO4 i bin kamapim litiam ain fosfet, ol manmeri i bin kisim pasin bilong yusim 'treathium iron phosphate' olsem 'lithium iron' wanpela komposit fosfet katod samting tasol. Tasol, long ol kompaun we i gat 'olivine' straksa, 'lithium iron phosphate' em i no wanpela tasol we ol i ken yusim olsem wanpela 'cathode material' insait long ol 'lithium-ion' bateri. Folem save bilong nau, i gat tu LiMnPO4, LiMnFePO4, LiVPO4, LiCoPO4, na planti ol narapela samting.
As bilong ol samting bilong 'lithium iron phosphate' i go bek long 1996, taim kampani bilong Japan, NTT, i painimaut olsem AMPO₄ (A em i wanpela alkali metal, M em i Co o Fe) wantaim olivine straksa, wantaim LiFeCoPO₄, ol i ken yusim olsem wanpela 'lithium{{1}y}ion battery cathode' samting. Bihain, ol i painimaut long Goodenough risets grup long Massachusetts Institute of Technology long Amerika, taim ol i wok long stadim ol 'framework compounds', olsem 'lithium iron phosphate material' i gat 'reversible property' bilong 'lithium-ion' (Li+) 'intercalation' na 'deintercalation'. Long Epril 23, 1997, Yunivesiti bilong Texas long Austin i bin putim wanpela 'patent' we nem bilong en "Cathode materials for rechargeable lithium secondary batteries" (WO1997010541), na dispela i makim stat bilong 'patent monopoly' long ol 'lithium iron phosphate' samting.
Pablikesen bilong ol olivine-structured phosphate (LiMPO4) katod materiel bilong Amerika na Japan long wankain taim i pulim bikpela luksave, i kirapim bikpela wok painimaut, na i go het hariap long wok bilong kamapim ol indastri. Taim yumi skelim wantaim ol tradisenel 'lithium-ion secondary battery cathode materials-spinel-structured lithium manganese oxide (LiMn₂O₄) na 'layered-structured lithium cobalt oxide' (LiCoO₂)-LiMPO₄ i gat planti na i no gat planti samting bilong envairomen polusen. Moa yet, sefti i kamap gutpela tru, na dispela i kirapim bikpela laik bilong ol risetsa na indastri.
Ol risets risal bilong ol yia i go pinis i soim olsem 'lithium iron phosphate' samting i gat gutpela 'olivine' straksa, na ol 'lithium-ion diffusion channels bilong en i no wankain olsem ol 'cathode' samting bilong bipo. Ol tradisenel 'cathode' samting i gat ol 'layered' o 'spinel' straksa, we i larim ol 'lithium ions' long muv hariap namel long ol 'layer' o long ol bikpela rot, na dispela i mekim ol samting i gat gutpela 'discharge performance'. Tasol, ol 'lithium-ion 'diffusion channels' insait long ol 'lithium iron phosphate' samting i gat wanpela 'dimensional', na dispela i min olsem insait long kristal i gat wanpela "tanel" tasol bilong 'lithium-ion 'diffusion', olsem na 'lithium-ion 'migration rate' i no bikpela tumas na 'diffusion' i sotpela. Moa yet aninit long ol 'high-rate discharge kondisen, ol intanel 'lithium ions' i no inap long go aut long taim, na dispela i save kamapim bikpela 'electrochemical polarization'.
Ol i ken wokim ol bateri long yusim 'pure lithium iron phosphate material' long strongim ol dispela tingting antap. Ol wok painimaut i soim olsem 'capacity utility' bilong 'pure lithium iron phosphate' samting i liklik tru, na bateri i save kisim hariap 'capacity decay' taim em i ron long baiskol. Piksa 2.1 i soim wok bilong wanpela 'lithium-ion coin cell' we man i raitim dispela buk i wokim wantaim 'hydrothermally synthesized pure lithium iron phosphate' (i no gat 'carbon coating'). Yumi ken lukim olsem bihain long samting olsem 15-pela 'charge-discharge' saikel, strong bilong bateri i go daun moa long 20 pesen. Olsem na, ol samting we i gat 'lithium iron phosphate' long en i no gutpela long ol 'lithium-ion' bateri sistem.
Long 2000, Hydro-Québec (H-Q), nesenel pablik yutiliti bilong Kanada, em i namba wan long putim ol 'patent' long putim ol samting long 'lithium iron phosphate', na tu, ol i yusim 'carbon coating' long ol samting bilong 'lithium iron phosphate'. Dispela i mekim na 'lithium iron phosphate' i gat bikpela 'specific capacity' na i skruim 'cycle life' bilong en i go moa long 2000 'cycles'. Dispela i makim stat bilong indastrialisesen proses bilong 'lithium iron phosphate' olsem wanpela 'cathode material'.
