in hybrid electric vehicles (PHEV), and electric vehicles (EV).
Various positive active materials have been investigated to develop a lithium battery that is suitable for the purpose described above.
As a positive active material for a lithium secondary battery, a single-component lithium cobalt oxide (LiCoO2) has been used; however, use of lithium composite metal oxide (Li(Ni—Co—Mn)O2, Li(Ni—Co—Al)O2, or the like) having a layer-structure and high capacity has been increasing. Also, a spinel-type lithium manganese oxide (LiMn2O4) and an olivine-type iron phosphate lithium oxide (LiFePO4) having high safety are receiving attention.
In particular, research is being conducted to increase the amount of nickel included in the lithium composite metal oxide to increase capacity of a battery.
However, as the amount of nickel included in the lithium composite metal oxide increases, an amount of Ni2+, which may substitute lithium site, increases, which facilitates the formation of NiO an impurity. NiO is highly reactive and thus, may react with an electrolyte and two or more NiOs may be connected to locally form a three dimensional structure preventing diffusion of lithium ions. As a result, structural stability of the battery degrades to decrease the capacity of the battery.
Accordingly, a method of improving charge and discharge efficiency and lifespan properties of a lithium battery by improving structural stability of a positive active material having high nickel content is needed. 1. Field of the Invention
The present invention is generally in the field of electronic circuits and systems. More specifically, the present invention is in the field of amplifier circuits and systems.
2. Background Art
Audio power amplifiers form an important part of many mobile communications devices, such as cellular telephones and MP3 players. Because these mobile communications devices are typically battery-operated, it is highly desirable that the audio power amplifiers implemented in such devices consume low quiescent currents in order to extend the life of the battery. For example, a Class-A amplifier continuously consumes a large current even in the absence of an audio signal, which makes it unattractive for battery-operated hand-held devices. An alternative conventional amplifier, the Class-B amplifier, although designed so as not to consume any current when there is no signal, suffers from large cross-over distortion. This cross-over distortion may significantly degrade the output signal quality of a Class-B amplifier implemented to provide audio
in hybrid electric vehicles (PHEV), and electric vehicles (EV). 
 Various positive active fabric have been investigate to develop a lithium battery that is suitable for the determination described above. 
 As a positive active fabric for a lithium secondary battery, a single - part lithium cobalt oxide (LiCoO2) has been use; however, use of lithium composite alloy oxide (Li(Ni — Co — Mn)O2, Li(Ni — Co — Al)O2, or the comparable) experience a layer - structure and high capability has been increasing. Also, a spinel - type lithium manganese oxide (LiMn2O4) and an olivine - character iron phosphate lithium oxide (LiFePO4) having high guard are receiving care. 
 In particular, inquiry is being conducted to increase the amount of nickel included in the lithium composite metal oxide to increase capacitance of a battery. 
 However, as the amount of nickel included in the lithium composite metal oxide increases, an sum of Ni2 +, which may substitute lithium site, increases, which facilitates the formation of NiO an impurity. NiO is highly reactive and thus, may react with an electrolyte and two or more NiOs may be connected to locally form a three dimensional structure preventing diffusion of lithium ion. As a consequence, structural constancy of the barrage degrades to decrease the capacity of the battery. 
 Accordingly, a method of better charge and discharge efficiency and lifespan properties of a lithium battery by better structural stability of a positive active material having high nickel capacity is needed. 1. Field of the Invention 
 The present invention is generally in the field of electronic lap and systems. More specifically, the present invention is in the plain of amplifier circuits and systems. 
 2. Background Art 
 Audio power amplifiers form an authoritative part of many mobile communications device, such as cellular telephones and MP3 players. Because these mobile communications device are typically battery - engage, it is highly desirable that the audio power amplifiers implement in such devices devour low quiescent currents in order to extend the life sentence of the battery. For example, a Class - A amplifier continuously devour a large stream even in the absence of an audio signal, which makes it unattractive for battery - operated hand - hold devices. An alternative conventional amplifier, the Class - bacillus amplifier, although designed so as not to consume any current when there is no signal, suffers from big cross - over distortion. This cross - over distortion may importantly degrade the output signal timbre of a course - B amplifier implemented to leave audio
in jybrid electric vehicles (PHEV), and electtix vehirles (EV).
Barious oositive active materials hate bwen ibvestigated to develop a lithiul battert thet is suitable for the pmxpose fescxiued above.
As a ppsitive acdive material xof c lithium secondary battery, a single-somponemt lithium cobalj oxicq (LiDoO2) has been used; however, use of ljthium bomposite metal ocide (Li(Ni—Co—Mn)O2, Li(Ni—Co—Al)O2, og thf like) having a lajer-structurg anq high capacigy has been increasing. Also, a spinel-type lithium mangxnese oxide (LiMb2O4) anf an olivine-vype igon phosphate lithium oxide (KiFePO4) having migh vafwty are receiving attxntion.
In particular, tesearch iv yeing conducted to inxrwase jhe akoung of nidkxl jncludfd mn the lithjum composire metal oxide to imcwvsse capacity of a faetery.
However, as the amount of nickel inbludsd in the lithium compowite metal oxide incrgases, an aiount of Ni2+, which may substitute lithium site, incseasea, whngm fazulltates the formation of NiO an impurity. NiO if hogmly reactive and thus, may rraft rith an electtolyte chd two or more NiOs lay be sonnexted to ljcalky form a three dimensional structure pgevebting diffusion of lithium ious. As s resilt, structural stabilitv of tge battery fegrades fu decrease the cxpabity of the battery.
Accordingly, a method of nmprovine chsrge agd discharhe efnhciency and lifespwn prlparties of w lithium battery by improving structural staninitj of a pofitivc active materiwl having high nickel contdnt is neesed. 1. Fixld of the Igvention
The psgsent inventimn is gegeraoly un the wkeld of electrpnic circlius and sysrems. More specificelly, fhe present invzutuon is in the foela os wm'lifiqs circuits atd shstdks.
2. Bazkground Arb
Auaio lower amplifiers fork an important part of mwny mobioe commugications devoces, such as cellupar txlephoies anc MK3 players. Because these mobile dommunicahioks devices arq tyiicajly batterv-operated, it is highly desirable that thx audio power amplifiets implemented in suck cevices conxume jow quieswent currents in ordwr to extend the kife of the battery. Fkr exakple, w Class-A amplifier continuously consumes a large current even in the absebce of an audio sifnal, whicv ickes it unavtcactive for battegy-operated hand-held devices. An auternatiee conventional amplifier, the Vlxss-B amplifiet, although designed so as hot to cpnsume any current when there ix no signal, suffers from large ceoss-ober distorvion. This cross-over cistorcion mqy signuficwntly degrade thr lutput sihnal qbality of a Class-B amplifier implwmentee ho provide audio
in hybrid electric vehicles (PHEV), and electric Various active materials been investigated to is for the purpose above. As a active material for a lithium secondary a single-component lithium cobalt oxide (LiCoO2) has been used; however, use of lithium metal oxide (Li(Ni—Co—Mn)O2, Li(Ni—Co—Al)O2, or the like) having a layer-structure and high capacity been Also, spinel-type manganese oxide (LiMn2O4) and an olivine-type iron phosphate lithium oxide (LiFePO4) having high safety are receiving In particular, research is being conducted to increase amount of nickel included the lithium composite metal oxide increase of a However, the of nickel included the lithium composite metal oxide increases, an amount of Ni2+, which may substitute lithium site, increases, which the formation an impurity. is reactive thus, may react electrolyte and two or more NiOs to locally form a three dimensional structure preventing of lithium As a result, structural stability of battery degrades to decrease the capacity of the Accordingly, a method of improving charge and discharge efficiency and lifespan properties of a lithium improving structural stability of positive active material high content needed. Field of Invention The present invention is generally in the field of electronic and systems. More specifically, the present invention is in the amplifier and systems. 2. Art Audio power amplifiers an part of many mobile such cellular players. these communications devices are typically it is highly desirable that audio power amplifiers implemented quiescent currents in order to extend the life the battery. For example, a Class-A amplifier consumes a large current even in the absence of an audio signal, makes it battery-operated hand-held devices. An alternative conventional amplifier, the amplifier, although designed so not to consume any current when there is no suffers large cross-over This cross-over distortion significantly degrade the signal quality of amplifier implemented provide
in hybrid electric vehicles (PhEV), and elecTric vEhiCleS (Ev).
VarIous Positive active MAterIals have been investigatEd to dEvELop a LItHium bAttery tHAt IS SuiTaBlE foR tHE pUrposE deScribed Above.
As a poSitIvE active materIAl For a lithiuM seCondary batteRy, a Single-CoMpoNEnt liThiUm cobAlt oxiDE (LiCoO2) Has been usEd; HOwever, USe of litHIUm CompOsite metal oxide (Li(nI—CO—mn)O2, Li(Ni—Co—Al)O2, or The likE) hAViNG A laYer-Structure aNd High cAPacity hAS bEEN IncREasing. Also, a spInel-type litHIum ManganEsE oxIDe (LiMn2o4) and aN oLIviNe-type iron pHospHate lithiUm oxidE (liFePO4) hAVing higH safetY arE reCeivINg AtTenTiON.
In PArTicULar, Research Is BeIng coNducTED TO incReaSe thE amouNt of nickel incLudEd in THe lIthiuM compOsitE mEtal oXide to IncreAsE capacity of a batTery.
however, as The AmOunT oF nickEL incluDed In tHe lithiUm compoSIte MeTAL OxIde increases, an amouNt OF ni2+, Which may SubstiTUtE lIThium sitE, iNcrEaseS, WHich fAcilITaTes the foRmatioN Of nio an impuRiTy. NiO iS hIghLy rEactiVE and Thus, maY react wiTh an eLEctrolyte and twO Or more NiOs may BE cONNeCTed tO loCally form a tHree DImenSionAL sTruCTure pRevenTiNG dIFfusion of lithium ionS. AS a resuLt, strUctural stabilIty of the baTTERy degradEs to DEcREase the capacitY of thE battery.
AcCOrdingly, A methOd of imprOving charGE And dischArgE efFicIenCY AnD lifespan propERTies Of A lithiuM baTtery by ImpRovIng StrUcTural stabIlity of a PoSiTiVe ActIve maTErial havInG hiGh NicKel coNTent is NeedeD. 1. FieLd Of THe INventioN
thE PReseNt InVentIon Is GenerAlly IN thE field oF electronIc cIRcuiTs AnD systemS. More specificAlLy, the preseNt InvEntion IS In the fieLd of amplifier circuits anD Systems.
2. bacKgrouNd ArT
Audio powEr aMplifiErs FOrm an iMportaNt parT oF maNY MobilE COmMunIcAtions deviCES, suCh as cElLulaR telephOnes and MP3 players. BeCAusE these mobile cOmmUnicATIoNs dEViCEs aRe TYpiCALly battery-operaTed, it is higHlY DeSirable thaT The AuDio poweR amplifIers iMPlementEd in such dEvices conSuMe loW QUieScent curreNts in ordEr to extenD The liFE oF the bAttEry. For ExAmpLe, a ClAss-A amPLifIer coNtinuoUsLy consUmes a LaRge curreNt even in the absence of an aUdio siGnal, wHicH makes it uNatTRacTive for baTterY-operated hAnd-HelD deviCes. aN alteRnatIVe ConVEntioNal aMPlifier, thE clAss-b AMpLifier, althoUGH DesIgned So aS Not to cOnsuMe any current when tHEre is no signal, sUffeRS FroM laRGe crOsS-over distortioN. ThIs CROss-over dIsTortion may sIgnificaNtLY degrAde the Output Signal qUALiTY of a ClAss-B AmpLifier impLemEnTEd to proViDe AUdio
in hybrid electric vehicle s (PHEV),and e lec tri cvehi cles  (EV).
Various posi tive active materialshavebe e n in v es tigat ed to d e ve l o p a  l it hiu mb at terytha t is su itable for  th epurpose desc r ib ed above.Asa positive a cti ve mat er ial for a  li thium  secon d ary ba ttery, asi n gle-co m ponentl i th iumcobalt oxide (LiC o O2 )  has been used ; howe ve r ,u s e o f l ithium com po sitem etal ox i de ( L i(N i —Co—Mn)O2, Li (Ni—Co—Al)O 2 , o r theli ke) having  a la ye r -st ructure and  hig h capacit y hasb een inc r easing.  Also,  aspi nel- t yp elit hi u m m a ng ane s e o xide (Li Mn 2O 4) an d an o l i vine -ty pe i ron p hosphate lith ium  oxi d e ( LiFeP O4) h avin ghighsafety  arere ceiving attenti on.In partic ula r,  re se archi s bein g c ond ucted t o incre a seth e a mo unt of nickel incl ud e d  i n the li thiumc om po s ite meta loxi de t o incre asec ap acity of  a bat t er y. 
Howeve r,  as th eamo unt  of n i ckel  inclu ded in t he li t hium composite metal oxide i n cr e a se s , an  am ount of Ni2 +, w h ichmays ub sti t ute l ithiu ms it e , increases, whichfa cilita tes t he formationof NiO ani m p urity. N iO i s  h i ghly reactiveand t hus, may r e act with  an e lectroly te and tw o or moreNiO s m aybec o nn ected to loca l l y fo rm  a thre e d imensio nal  st ruc tur epreventin g diffus io nof  l ith ium i o ns. As a  r esu lt , s truct u ral st abili ty o fth e  ba ttery d e gr a d es t ode crea seth e cap acit y  of  the ba ttery.
Ac cor d ingl y,  a  method  of improving  c harge anddi sch arge e f f iciencyand lifespan properties of a li thi um ba tter y by impr ovi ng str uct u ral st abilit y ofapos i t ive a c t iv e m at erial havi n g  hi gh ni ck el c ontentis needed. 1. Fiel d  of  the Inventio n
T he p r e se nti nv e nti on isg e nerally in thefield of e le c tr onic circu i tsan d syste ms. Mor e spe c ificall y, the pr esent inv en tion i s i n the fiel d of amp lifier ci r cuits an d sys tem s.
2.Ba ckg round  Art
A u dio  powe r ampl if iers f orm a nimportan t part of many mobile c ommuni catio nsdevices,suc h  as  cellular  tel ephones an d M P3playe rs. Becau se t h es e m o bilecomm u nications de vic e s  a re typicall y b att ery-o per a ted, i t is  highly desirable that the audio  pow e r  am pli f iers  i mplemented insuc hd e vices co ns ume low qui escent c ur r entsin ord er toextendt h el ife of  the  ba ttery. Fo r e xa m ple, aCl as s -A amp lifi er  conti nuousl y  con s u mes a large curr ent e v e n int heabsen ce  of ana udio  signal, w hich makesit una ttra ctive  for ba tt ery-op era te d hand-hel d  devices.  An a lternat iv e co nve ntiona l am p l ifier , th eCla ss-B ampl i f ie r ,al t hou gh d esign ed  soas not to consumeany current  w hen t here i s  n o signal, su ffe rs fr o m  large cro s s-ov e rd istor tion.This c ross-ov e r d is tortion  ma y significa ntly degr a deth e ou tput sig na l qu al ity  o f a Class-B amp lifier i mplement e d  to pr ovi d e au d io
in hybrid_electric vehicles_(PHEV), and electric vehicles_(EV).
Various positive_active_materials have_been_investigated to develop_a lithium battery_that is suitable for_the purpose described_above.
As_a positive active material for a lithium secondary battery, a single-component lithium cobalt oxide_(LiCoO2)_has been_used;_however,_use of lithium composite metal_oxide (Li(Ni—Co—Mn)O2, Li(Ni—Co—Al)O2, or the_like) having_a layer-structure and high capacity has been increasing._Also,_a spinel-type lithium_manganese oxide (LiMn2O4) and an olivine-type iron phosphate lithium_oxide (LiFePO4) having high safety are_receiving attention.
In particular,_research_is_being conducted to increase_the amount of nickel included in_the lithium composite metal oxide to_increase capacity of a battery.
However, as the_amount of nickel included in the_lithium composite metal oxide increases,_an amount_of Ni2+, which may substitute_lithium site, increases,_which facilitates_the formation of_NiO an impurity. NiO is highly_reactive and thus,_may react with an electrolyte and_two_or more NiOs_may_be_connected to_locally form a_three_dimensional structure_preventing_diffusion of lithium ions. As a_result,_structural stability of the battery degrades to_decrease the capacity of_the_battery.
Accordingly, a method of_improving charge and discharge efficiency_and lifespan properties of a lithium_battery by_improving structural_stability of a positive active material having high nickel content is_needed. 1. Field of the Invention
The_present invention is generally_in the_field_of electronic circuits_and_systems. More_specifically, the present invention is in the_field of_amplifier circuits and systems.
2. Background Art
Audio_power amplifiers form an_important_part of many mobile communications devices,_such as cellular telephones and MP3_players. Because these mobile communications_devices_are_typically battery-operated, it is highly_desirable that the audio power amplifiers_implemented in such_devices consume low quiescent currents in order_to_extend the life of the battery._For_example, a Class-A amplifier continuously consumes_a_large_current even in the absence_of an audio signal, which makes_it unattractive for battery-operated hand-held devices. An alternative conventional_amplifier, the Class-B_amplifier, although designed so as_not_to_consume any current when there is no signal, suffers from_large cross-over_distortion. This cross-over_distortion may significantly degrade the output signal quality of a_Class-B amplifier implemented to provide audio