| Increasing specific capacity and cycle stability has always been an important topic in the research field of lithium ion batteries.Silicon has become a good potential anode material for next-generation lithium-ion batteries due to its high theoretical capacity of 4,200 mA h g-1.However,silicon particles generate a more than 300%volume expansion during cycling,which severely limits the cycle stability of the battery.Herein,a conductive polymer is prepared as a binder to accommodate and alleviate the volume expansion of the particles,thereby improving the specific capacity and cycle performance of the lithium ion battery.A polyaniline/poly?acrylic acid?conductive polymer is synthesized as a binder by in-situ compounding.Among the anode materials,polyaniline constitutes a three-dimensional conductive frame.The polyaniline together with hydroxyl groups,which present on the silicon particles surface,is linked to the poly?acrylic acid?by chemical bonds,so that the structure of the anode becomes more stable.As a result,the composite electrode performs extremely well in deep charging and discharging process:from 20to 1000 cycles,the capacity is only attenuated by 18%.It is found that the influence of different carboxymethyl cellulose binders on the cycle performance of lithium ion batteries was significantly different when performing comparison experiment.In order to deeply understanding the effect of carboxymethyl cellulose binders on the electrochemical performance of lithium ion batteries,experiments with sodium carboxymethyl cellulose and carboxymethyl cellulose as binders were operated.The results showed that the battery had a higher specific capacity when the sodium carboxymethyl cellulose was used as the binder with the first discharge specific capacity of 2559 mA h g-1.When the carboxymethyl cellulose is used as a binder,the cycle stability of the battery is more excellent:the capacity retention amount is as high as 90%after 100cycles. |
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