我們都知道，鋰電池隨著充放電次數的增加，容量會越來越少，直接表現就是鋰電池的性能越來越差。那么都有哪些因素影響到鋰電池的性能呢？
提升鋰電池倍率對電池性能影響有哪些？
        影響鋰電池容量的影響因素很多，使用溫度、充放電電流、充放電截止電壓等因素都會影響鋰離子電池的衰降速度。造成鋰電池容量衰降的機理可以分為三類：內阻和極化增加、正負極活性物質損失、Li損失。
不同的外部因素對這三者的影響也各不相同。例如LiFePO4材料的鋰電池具有非常好的循環性能，但是不同的使用條件對鋰電池循環壽命有著重要的影響。試驗證明對26650鋰電池進行15C脈沖放電和15C連續放電，兩種放電制度對于26650鋰電池具有完全不同的影響。15C脈沖放電的26650鋰電池容量衰降非常快，充放電40次后就無法再進行15C放電，但是仍然能夠進行1C放電。而15C連續放電電池容量衰降較慢，60次以后仍然能夠進行15C放電，但是1C倍率的衰降速率要快于15C脈沖放電。
      機理分析得出結論：15C脈沖放電的電池在負極的SEI膜中出現更多的LiF，而LiF對鋰離子擴散的阻礙更大，使得電池的Li+擴散阻抗和電荷交換阻抗迅速增加，從而使得電池在充放電過程中極化電壓過大，從而導致LiFePO4大電流放電能力迅速下降。
       鋰電池的充電策略對于鋰電池壽命衰降影響的研究，能夠更好的指導我們對鋰離子電池的設計。以下就不同充電控制策略對鋰離子電池壽(shou)(shou)命衰(shuai)降的(de)影響，研究了(le)其(qi)作用機理，提出鋰離(li)子(zi)電(dian)(dian)池的(de)壽(shou)(shou)命衰(shuai)降模型。研究試驗表明(ming)，當充電(dian)(dian)電(dian)(dian)流(liu)和(he)截(jie)(jie)止(zhi)(zhi)電(dian)(dian)壓超過(guo)一定的(de)數值時，鋰離(li)子(zi)電(dian)(dian)池的(de)衰(shuai)降將被極大的(de)加(jia)速(su)，為了(le)降低(di)鋰離(li)子(zi)電(dian)(dian)池的(de)衰(shuai)降速(su)率，需要針對不同的(de)體系，需要選擇合適的(de)充放(fang)電(dian)(dian)電(dian)(dian)流(liu)和(he)截(jie)(jie)止(zhi)(zhi)電(dian)(dian)壓。

       從數據可以看到，隨著充電的倍率的加大，鋰離子電池的衰降速率也在快速增加，并且從曲線的斜率來看，電池的衰降速度存在三個不同的階段，前期衰降速度較快的階段（階段1），中間衰降速度較慢的穩定階段（階段2），和后期的衰降速率加速階段（階段3）。針對三個階段電池的衰降機理的研究認為，階段1可能是因為電池SEI膜生長需要消耗一部分Li+，因此衰降速度較快。在階段2隨著SEI膜結構的穩定，內部較為穩定，因此衰降速度較慢，在階段3隨著電池老化，開始發生活性物質損失，電極活性界面減少，導致電池對于電流十分敏感。圖C是針對不同的截止電壓對電池衰降速度影響的實驗，從實驗結果可以看到，當把充電截止電壓提高到4.3V時會導致電池的循環性能急劇惡化，降低充電截止電壓可以有效的改善電池的循環性能。
提升鋰電池倍率對電池性能影響有哪些？
      對電池的動態內阻分析如下圖所示，從圖a測試結果來看，當充電電流小于1C時，電池動態內阻隨著電池循環的變化趨勢幾乎時一樣的，但是當充電電流超過1C時，電池動態內阻增加速度會隨著充電速率的增加而快速增加。從圖b的測試結果來看，當充電截止電壓為4.3V時，電池動態內阻增加非常迅速表明高截止電壓會惡化電池的動力學條件，截止電壓為4.1V和4.2V時電池動態內阻增加較為緩慢。
從上述分析我們可以注意(yi)到(dao)，無論(lun)是(shi)(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)還是(shi)(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)截止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)都(dou)存在(zai)一個值(zhi)(zhi)(zhi)，當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)或者電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)超(chao)過這(zhe)個值(zhi)(zhi)(zhi)時(shi)就(jiu)會導致電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池衰(shuai)降加(jia)速(su)(su)，對(dui)于(yu)上述電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池這(zhe)個值(zhi)(zhi)(zhi)是(shi)(shi)1C和(he)(he)4.2V，當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)和(he)(he)截止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)超(chao)過這(zhe)個值(zhi)(zhi)(zhi)后就(jiu)會加(jia)速(su)(su)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)衰(shuai)降，當(dang)小于(yu)這(zhe)個值(zhi)(zhi)(zhi)時(shi)，提(ti)高(gao)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)和(he)(he)截止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)并(bing)不(bu)會顯著(zhu)的(de)增加(jia)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)衰(shuai)降速(su)(su)度。對(dui)于(yu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)和(he)(he)截止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)對(dui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池衰(shuai)降速(su)(su)度影響(xiang)的(de)機理研究顯示，當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)低于(yu)1C時(shi)主(zhu)要影響(xiang)的(de)是(shi)(shi)正負極(ji)活性物(wu)質損失(shi)(shi)(shi)，而截止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)低于(yu)4.2V時(shi)影響(xiang)的(de)主(zhu)要是(shi)(shi)Li損失(shi)(shi)(shi)，當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)和(he)(he)截止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)高(gao)于(yu)這(zhe)個值(zhi)(zhi)(zhi)時(shi)，則會顯著(zhu)的(de)加(jia)速(su)(su)正負極(ji)活性物(wu)質損失(shi)(shi)(shi)和(he)(he)Li損失(shi)(shi)(shi)。