新能源材料与技术Renewable Energy: Materials and TechnologiesL5: Energy Storage and Batteries (II)DrYiminChaoy.chao@uea.ac.ukwww.uea.ac.uk/chemistry/people/faculty/chao
新能源材料与技术 Renewable Energy: Materials and Technologies L5: Energy Storage and Batteries (II) Dr Yimin Chao y.chao@uea.ac.uk www.uea.ac.uk/chemistry/people/faculty/chao
Backtofundamentals·lmprovedcyclelifeof newest lead-acidbatteriesvariants·Otherweaknessoflead-acidbatteryremainsLowspecificenergyReduceweight-4o%inseparators,electrolyteandcaseElectrolyte involved in electrode chemistrydoesn't contribute to energyIntrinsicchemistryproblemsOnly2 Vpotential, doubling as in Li batteries doubles specific energy
Back to fundamentals •Improved cycle life of newest lead-acid ba:eries variants •Other weakness of lead-acid ba:ery remains Low specific energy Reduce weight – 40% in separators, electrolyte and case Electrolyte involved in electrode chemistry, doesn’t contribute to energy Intrinsic chemistry problems Only 2 V potenBal, doubling as in Li baDeries doubles specific energy
Simplest battery designSeparatorCurrentcollectorCurrentcollectorCathodeAnodeMustconsidercapacityofbothcomponents
Anode Cathode Current collector Current collector Separator Must consider capacity of both components Simplest ba:ery design
Li-ion batteries
Li-ion ba:eries
Li-ion batteriesBasedonthehalfcellreactionLi(s) = Li++ eWhylithium?Most electropositive element, E°= -3.04 V, light element, AW = 6.94 g mol-1TwoaspectsStorage of Li (anode)Storage of Li+(cathode)Associatedhalf cell reaction depending on the material used
Based on the half cell reacDon Li(s) = Li++ e Why lithium? Most electroposiDve element, E°= -3.04 V, light element, AW = 6.94 g mol-1 Two aspects Storage of Li (anode) Storage of Li+(cathode) Associated half cell reacBon depending on the material used Li-ion ba:eries