ATLConfidential491825LowCapacityFA背景&原因調(diào)查2491825的從2月中下旬開始連續(xù)容量抽檢不通過，對比之前的抽檢通過率~80%而言非常異常。分析容量分布，發(fā)現(xiàn)呈雙峰。主峰Mean~213.5mAh，屬于正常；小峰Mean~206mAh，屬于異常。3By膜卷分析發(fā)現(xiàn)低容量主要來自S2215012100072、S2215020300070。其中S2215012100072更異常。Mean偏小，且呈雙峰背景&原因調(diào)查4受這兩個膜卷（~230K電芯）的影響，491825的容量Mean在2月份一直下降，到了3月初已經(jīng)降到Mean~210mAh。Mean~210mAh背景&原因調(diào)查5將容量與注液前的重量做相關，發(fā)現(xiàn)容量與重量呈很好的相關。參考2014年12月份Minicell陰極重量偏輕導致低容量的經(jīng)驗，初步判定此次低容量仍然陰極重量偏輕有關。此處異常點是稱重異常背景&原因調(diào)查陰極涂膜工序極片留樣分析_稱小圓片重量6將陰極涂膜工序極片留樣用小沖頭（面積154.025mm^2）沖小圓片稱重，發(fā)現(xiàn)：邊料偏輕~10mg(單面)/20mg（雙面）頭部削薄區(qū)偏輕~15mg(單面)/30mg（雙面），尾部削薄區(qū)正常。單面雙面重輕陰極涂膜工序極片留樣分析_估算容量7根據(jù)沖小圓片稱重計算理論容量值：整體容量值比設計值偏小~1mAh邊料最邊上一條容量值偏低較多，~8mAh，倒數(shù)第二條容量值偏低~2.5mAh。

12345678910111213單面A332338341339343342346347345347345345333B347352353356362356355356355357359354345C347350353357355354355358361356358353347D345355356355355362358357357360354356344

E350355359357358360359357358354354356348雙面A617641632639633635641637643644646640621B639661658660661659662663662661666649645C632655658657660658656657656660663652633D653662659661660659658658661660661650634

E640650665660659661662663659661663655633小條重量設計值1.3811.3811.3811.3811.3811.3811.3811.3811.3811.3811.3811.3811.381實際值1.3331.3761.3811.3811.3851.3811.3821.3831.3831.3881.3941.3701.330

實際值(扣除小沖頭誤差)1.3251.3681.3721.3731.3761.3731.3741.3751.3741.3791.3851.3621.322容量設計值214.4214.4214.4214.4214.4214.4214.4214.4214.4214.4214.4214.4214.4實際值206.9213.6214.3214.3214.9214.4214.5214.7214.6215.4216.3212.7206.4

實際值(扣除小沖頭誤差)205.6212.3213.0213.0213.6213.1213.2213.4213.3214.1215.0211.4205.1Conclusion&Correctiveaction8Conclusion491825容量低異常是陰極極片偏輕導致。陰極極片重量偏輕是邊料和削薄。Correctiveaction切入小沖模監(jiān)控涂膜邊料------------------------------------------------------------------------------ME/PRJ2/10/2015Done小沖模的誤差問題繼續(xù)研究---------------------------------------------------------------------------ME/PRJ4/7/2015Update涂膜邊料偏輕的分析和改善---------------------------------------------------------------------------ME/PRJ4/7/2015Update削薄區(qū)的控制,如何避免削過頭-----------------------------------------------------------------------ME/PRJ4/7/2015UpdateAppendix_小沖頭誤差9大圓小圓1小圓2小圓3小圓4組別大圓小圓1小圓2小圓3小圓4小圓平均大圓/10小圓-大圓誤差%A0.70000.07010.07020.07040.07080.07040.07000.00040.56%B0.70120.07030.07040.07050.07080.07050.07010.0004C0.70220.07090.07030.07070.07070.07070.07020.0004D0.70290.07050.07080.07030.07030.07050.07