采用酸处理尖晶石型LiMn2O4的方法合成了λ-MnO2。通过X-射线衍射(XRD)、扫描电子显微镜(SEM)和恒流放电测试等对λ-MnO2的结构、形貌和电化学性能进行了研究。结果表明,合成的λ-MnO2具有类似于LiMn2O4的尖晶石型晶体结构,形貌规则,晶粒细小,粒径分布均匀;将其作为正极材料组装成Li-MnO2电池,以0.025C倍率放电,得到了3.98V和2.88V两个放电平台,放电比容量达268mAh/g,且其放电平台和比容量受放电倍率影响较小。
The λ-manganese dioxide (λ-MnO2) was synthesized by acidifying spinel lithium manganese dioxide (LiMn2O4). The crystalline structure, morphology and electrochemical properties of λ-MnO2 were investigated by X-ray diffraction, scanning electron microscopy and galvanostatic discharge test. The results show that λ-MnO2 has the same spinel-type structure like LiMn2O4, and it has small particle size, regular morphology, and uniform distribution of particle size. λ-MnO2 delivers a discharge capacity of 268 mAh/g at a rate of 0.025 C in discharge plateau 3.98 V and 2.88 V. Therefore, λ-MnO2 is a promising cathode material for primary Li-MnO2 batteries, and its discharge capacity and discharge plateau are scarcely influenced by discharge rate.