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在常压条件(电压范围为2.7～4.2 V)下，富锂正极材料电化学性能的研究结果显示该材料具备显著优势。在常温环境下进行的1 C倍率充放电循环测试中，材料的容量基本保持稳定，经2 500次循环后，容量剩余率达103.4%(对比2.7～4.3 V电压区间测试时，材料经200次循环后容量剩余率仅为90%左右)。循环初期，放电容量的不断提升以及X射线衍射(XRD)组分精修结果均表明，在常压条件下Li2MnO3存在缓慢分解现象，并在充放电过程中发挥补锂作用。进一步将富锂材料与锰酸锂以不同质量比复合，作为正极活性材料组装成电池。实验结果表明，在富锂材料添加量为50%(质量分数)的复合体系中，电池在常温下以1 C倍率进行充放电循环500次后，容量基本不衰减；在45℃高温环境下，以1 C倍率进行充放电循环400次后，容量剩余率仍高达94.3%。富锂材料的补锂作用有效减缓了锰酸锂在前期循环中的大幅容量衰减，使锰酸锂性能提升超过20%，同时提高了电池体系的能量密度。
Abstract：Under atmospheric pressure conditions (voltage range 2.7 to 4.2 V),research on the electrochemical performance of lithium-rich cathode materials has shown significant advantages.In 1 C rate charge-discharge cycle tests conducted at room temperature,the material's capacity remained largely stable,with a capacity retention rate of 103.4%after 2 500 cycles (compared to around 90%after 200 cycles in the 2.7 to 4.3 V voltage range).The continuous increase in discharge capacity during the early stages of cycling and the refined X-ray diffraction (XRD)results indicate that Li2MnO3 undergoes slow decomposition under atmospheric pressure and plays a lithium-supplementing role during charging and discharging.Further,the composite material consisting of lithium-rich materials and lithium manganate was assembled into batteries at different mass ratios as active cathode materials.Experimental results show that in the composite system with 50% mass fraction of lithium-rich material,the battery retains its capacity almost unchanged after 500 charge-discharge cycles at 1 C rate at room temperature;even after 400 charge-discharge cycles at 1 C rate in a 45℃high-temperature environment,the capacity retention rate remains as high as 94.3%.The lithium-supplementing effect of the lithium-rich material effectively mitigates the substantial capacity decay of lithium manganate in the initial cycles,enhancing the performance of lithium manganate by over 20%,while also increasing the energy density of the battery system.
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基本信息:
DOI：10.19996/j.cnki.ChinBatlnd.2025.03.006
中图分类号:TQ131.11;TM912
引用信息:
[1]谈亚军,冯明燕,王正伟.富锂正极材料在常压下的电化学性能及应用[J].电池工业,2025,29(03):179-183.DOI:10.19996/j.cnki.ChinBatlnd.2025.03.006.
基金信息: