The conversion reaction mechanism of bimetallic Ni–Fe hydroxycarbonate and its encapsulation in carbon nanospheres for achieving excellent Li-ion storage performance
作者:Jin-Sung Park、Jeong Hoo Hong、Su Hyun Yang、Yun Chan Kang
DOI:10.1039/d0ta04305b
日期:——
the NiFeHC material, amorphous NiFeHC was formed within the shells of hollowcarbon nanospheres via in situ precipitation, yielding a-NiFeHC@C. a-NiFeHC@C exhibited stable cycle performance up to 700 cycles and high rate performance, where a discharge capacity of 251 mA h g−1 was achieved at a high current density of 30 A g−1. The synergy of the heterointerface and encapsulation of amorphous NiFeHC within
仍在寻找具有理想组成的锂离子电池(LIB)最佳阳极材料。在此,研究了由两个过渡金属阳离子和两个阴离子化合物组成的羟基碳酸镍铁(NiFeHC)的锂存储机理。通过各种分析工具以及原位和异位技术,发现从第二个循环开始发生以下可逆转化反应:(1)M(OH)2 + MCO 3 + 4Li + + 4e - ↔2M + Li 2 CO 3 + 2LiOH(M = Ni,Fe),(2)Li 2 CO 3 +(4 + 0.5 x)Li+ +(4 + 0.5 X)在线- ↔3Li 2 O + 0.5Li X Ç 2( X = 0,1,2),和(3)的LiOH + 2LI + + 2e中- ↔栗2 O + LiH的。众所周知,由于存在形成固有内部电场的异质界面,具有不同带隙的异质结构复合材料表现出有吸引力的电化学性能。当作为阳极进行测试时,结晶的NiFeHC材料在以1 A g -1循环时的初始循环中显示出1221
Interplay between Chemical Composition and Cation Ordering in the Magnetism of Ni/Fe Layered Double Hydroxides
We report the synthesis of a family of ferrimagnetic NiFe layered double hydroxides (LDHs) with a variable Ni2+/Fe3+ in-plane composition of [Ni1-xFex(OH)(2)]-(CO3)(x)/(2)center dot yH(2)O (x = 0.20, 0.25, and 0.33) by following a modified homogeneous precipitation. These layered magnets display high crystallinity, homogeneous hexagonal morphologies, and micrometric size that enable their quantitative exfoliation into single layers by sonomechanical treatment of the solids in polar solvents This was confirmed by dynamic light scattering,. UV-vis spectroscopy, high resolution transmission. electron microscopy, and atomic force. microscopy methodologies to study the resulting steady suspensions. Our magnetic study reflects that the iron content in the LDH layers controls the overall magnetism of these lamellae. Hence, the gradual replacement of Ni2+ with Fe3+ centers introduces a larger amount of " antiferromagnetically coupled Fe OH Fe pairs across the layers, provoking that the compound with the highest Fe/Ni ratio displays spontaneous magnetization at higher temperatures (T-irr = 15.1 K) and the hardest coercive field (3.6 kG). Mossbauer spectroscopy confirms that the cation distribution in the layers is not random and reflects the occurrence of Fe clustering due to. the higher affinity of Fe3+ ions to accommodate other homometallic centers in their surroundings. In our opinion, this clarifies the origin of the glassy behavior, also reported for other magnetic LDHs, and points out spin frustration as the most likely cause.
High-performance, long lifetime chloride ion battery using a NiFe–Cl layered double hydroxide cathode
NiFe–Cl layered double hydroxide (LDH) is proposed as a high-capacity and long lifetime cathode material for chloride ion batteries (CIBs), which delivers a maximum capacity of 350.6 mA h g−1 and a long lifetime of 800 cycles.
NiFe-Cl 层状双氢氧化物(LDH)被提出作为氯离子电池(CIB)的高容量、长寿命阴极材料,其最大容量为 350.6 mA h g-1,长寿命为 800 次循环。