高镍三元正极材料后处理降碱工艺

以高镍含量镍钴锰氢氧化物、氢氧化锂为原料,采用高温固相法合成锂离子电池正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2(NCM811)。温度为750~850℃、n(Li)∶n(Ni+Co+Mn)为1.02∶1.00~1.08∶1.00,合成的NCM811材料保持纯相,但材料中残留的碱性杂质仍然较多。通过引入磷酸二氢铵、纯水淋洗等手段,可较为简便地处理残留的碱性杂质。与未处理的相比,淋洗降碱后的样品在3.0~4.3 V充放电,0.5 C、1.0 C及2.0 C倍率性能约有1%的降低,但0.1 C首次充放电效率由89.1%上升到93.0%,1.0 C放电比容量由179.2 m Ah/g上升为181.8 m Ah/g,循环100次,容量保持率由90.8%上升到94.1%。

Alkaline impurity post-treatment in high nickel ternary cathode material

LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material for Li-ion battery was synthesized by using nickel-cobalt-manganese hydroxide and lithium hydroxide through solid-state sintering process.When the temperature was in 750-850 ℃ and n(Li) ∶ n(Ni + Co + Mn) was in 1.02∶1.00-1.08∶ 1.00,the synthesized NCM811 material remained pure phase,but the residual impurities in the material were still kept at a high level.The residual alkaline impurities could be easily treated through the introduction of ammonium di-hydrogen phosphate and pure water elution.Compared with the untreated samples,0.5 C,1.0 C and 2.0 C rate performance of the samples in 3.0-4.3 V were decreased about 1％,while initial charge-discharge efficiency of 0.1 C was increased from 89.1％ to 93.0％,specific discharge capacity of 1.0 C was increased from 179.2 mAh/g to 181.8 mAh/g.At the 100th cycle,the capacity retention rate was increased from 90.8％ to 94.1％.