需要金幣： 1000 個金幣 |
資料包括：完整論文 |  |
 |
| 轉換比率：金額 X 10=金幣數量， 例100元=1000金幣 | 論文字數：10181 |  | |
| 折扣與優(yōu)惠：團購最低可5折優(yōu)惠 - 了解詳情 | 論文格式：Word格式(*.doc) |  |
摘 要:本論文采用無焰燃燒合成法，制備5V鋰離子電池正極材料LiNi0.5Mn1.5O4，在400℃時焙燒時間為30min，1h，3h，6h，12h，取出空冷制成的活性物質，研究了相同溫度不同焙燒時間對電性能的影響。 循環(huán)性能研究發(fā)現，當焙燒時間為30min時，其初始放電容量為80mAh/g，首次充放電效率為96%，經過30次循環(huán)后容量為79mAh/g，容量衰減率為1.25%；電流密度從30mA/g變大為75mA/g，放電容量下降為70mAh/g，在75mA/g下循環(huán)30次后容量為65 mAh/g，循環(huán)性能較好。當焙燒時間為1h時，初始放電容量為131mAh/g，首次充放電效率為98.6%，經過30次循環(huán)后容量為126mAh/g，容量衰減為3.8%；電流密度從30mA/g變大為75mA/g，放電容量下降為89mAh/g，在75mA/g下循環(huán)30次后容量為85mAh/g，循環(huán)性能很好。當焙燒時間為3h時，其初始放電容量為80mAh/g，首次充放電效率為95.7%，30次后放電容量為76mAh/g，容量衰減率為5%；電流密度從30mA/g變大為75mA/g，放電容量下降54mAh/g，在75mA/g下循環(huán)30次后容量53mA/g，循環(huán)性能好。當焙燒時間為6h時，初始放電容量為110mA/g，首次充放電效率96.2%，經過30次循環(huán)后容量105mA/g容量衰減率為4.5%；電流密度從30mA/g變大為75mA/g，放電容量下降為100mA/g，在75mA/g下循環(huán)30次后容量為95mA/g，循環(huán)性能好。當焙燒時間為12h時，其初始放電容量為115mA/g，首次充放電效率為95.8%，經過30次循環(huán)后放電容量為110mAh/g，容量衰減率為4.3%；電流密度從30mA/g變大為75mA/g，放電容量下降105mAh/g，在75mA/g下循環(huán)30次后容量105mAh/g，循環(huán)性能好。 放電曲線表明，焙燒時間對放電比容量影響較大，在一定溫度范圍內隨焙燒時間的升高而增大，放電比容量增加，合成材料的性能增強，但若焙燒時間過長反而會使放電比容量降低，材料性能減弱。其中,電性能最好的樣品為400oC時焙燒時間為3h所得樣品,其初始容量為80mAh/g,30次循環(huán)后,容量衰減率為5%，電池的充放電平臺高且穩(wěn)定，電池的充放電循環(huán)穩(wěn)定性較好。 關鍵詞： 無焰燃燒法，鋰離子電池， LiNi0.5Mn1.5O4， 5V正極材料
ABSTRACT:This paper adopted themethod of flameless combustion synthesis, investigating the influence of same temperature and different sintering conditions on electrical properties by preparing 5V lithium-ion battery cathode material LiNi0.5Mn1.5O4 under 30min, 1h, 3h, 6h, 12h at 400 ℃ and obtaining the living contents produced by cold air. Cycle performance study found that, when roasting time was 30min, the initial discharge capacity was 80mAh / g, the first charge-discharge efficiency of 96%, after 30 cycles, capacity was 79mAh / g, the rate of capacity decay was 1.25%; current density changed from 30mA / g to75mA / g, the discharge capacity decreased to 70mAh / g, at 75mA / g, after 30 cycles at a capacity of 65mAh / g, the cycle performance was better. When roasting time was 1h, the initial discharge capacity was 131mAh / g, the first charge-discharge efficiency was 98.6% after 30 cycles, the capacity was 126mAh / g, the capacity declined to 3.8%; current density changed from 30mA / g to 75mA / g, the discharge capacity decreased to 89mAh / g, in 75mA / g after 30 cycles under the capacity of 85mAh / g, the cycle performance was good. When the roasting time was 3h, the initial discharge capacity was 80mAh / g, for the first time, the first charge-discharge efficiency was 95.7%, after 30 cycles, the discharge capacity was 76mAh / g, the rate of capacity decay was 5%; current density changed from 30mA / g to 75mA / g, the discharge capacity decreased to 54mAh / g, at 75mA / g, after 30 cycles under the capacity of 53mA / g, cycle performance is very good. When the roasting time was 6h, the initial discharge capacity was 110mA / g, the first charge-discharge efficiency was 96.2%, after 30 cycles, the rate of decay of the capacity was105mA / g 4.5%; current density changed from 30mA / g to 75mA / g, the discharge capacity dropped to 100mA / g, at 75mA / g after 30 cycles under the capacity of 95mA / g, cycle performance was good. When baking time was 12h, the initial discharge capacity was 115mA / g, the first charge-discharge efficiency was 95.8%, after 30 cycles, the discharge capacity was 110mAh / g, the decay rate of capacity was 4.3%; current density changed from 30mA / g to 75mA / g, the discharge capacity decreased to 105mAh / g, at 75mA / g after 30 cycles under the capacity of 105mAh / g, cycle performance was good. Discharge curve showed that: the baking time had a greater impact on the discharge capacity. At a certain temperature range, the discharge capacity increased with the increase of sintering time, when discharge capacity increased, the performance of synthetic materials increased. But if the baking time was too long so the discharge capacity would decrease, the performance of synthetic materials increased. Among them, the best sample of the electrical properties was the sample that its roasting time was 3h under 400 ℃ , with an initial capacity of 80mAh / g, after30 cycles, the rate of capacity decay was 5%, the battery charge and discharge platform was high and stable , the stability of battery charge-discharge cycle was better. Keywords: the method of flameless combustion， lithium-ion battery， LiNi0.5Mn1.5O4，5V cathode materia |
