Chong Shaokun, Li Ting, Qiao Shuangyan, Yang Yi-Chun, Liu Zhengqing, Yang Jing, Tuan Hsing-Yu, Cao Guozhong, Huang Wei
Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi'an 710072, China.
Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
ACS Nano. 2024 Jan 30;18(4):3801-3813. doi: 10.1021/acsnano.3c12215. Epub 2024 Jan 18.
Sodium-ion batteries (SIBs) have been extensively studied owing to the abundance and low-price of Na resources. However, the infeasibility of graphite and silicon electrodes in sodium-ion storage makes it urgent to develop high-performance anode materials. Herein, α-MnSe nanorods derived from δ-MnO (δ-α-MnSe) are constructed as anodes for SIBs. It is verified that α-MnSe will be transferred into β-MnSe after the initial Na-ion insertion/extraction, and δ-α-MnSe undergoes typical conversion mechanism using a Mn-ion for charge compensation in the subsequent charge-discharge process. First-principles calculations support that Na-ion migration in defect-free α-MnSe can drive the lattice distortion to phase transition (alpha → beta) in thermodynamics and dynamics. The formed β-MnSe with robust lattice structure and small Na-ion diffusion barrier boosts great structure stability and electrochemical kinetics. Hence, the δ-α-MnSe electrode contributes excellent rate capability and superior cyclic stability with long lifespan over 1000 cycles and low decay rate of 0.0267% per cycle. Na-ion full batteries with a high energy density of 281.2 Wh·kg and outstanding cyclability demonstrate the applicability of δ-α-MnSe anode.
由于钠资源丰富且价格低廉，钠离子电池（SIBs）已得到广泛研究。然而，石墨和硅电极在钠离子存储方面的不可行性使得开发高性能负极材料变得迫在眉睫。在此，由δ-MnO衍生的α-MnSe纳米棒（δ-α-MnSe）被构建为SIBs的负极。实验证实，在首次钠离子嵌入/脱出后，α-MnSe会转变为β-MnSe，并且在随后的充放电过程中，δ-α-MnSe通过锰离子进行电荷补偿，经历典型的转化机制。第一性原理计算表明，在无缺陷的α-MnSe中，钠离子迁移在热力学和动力学上都能驱动晶格畸变至相变（α→β）。形成的具有坚固晶格结构和小钠离子扩散势垒的β-MnSe具有出色的结构稳定性和电化学动力学性能。因此，δ-α-MnSe负极具有优异的倍率性能和卓越的循环稳定性，在超过1000次循环中具有长寿命，且每循环的衰减率低至0.0267%。具有281.2 Wh·kg高能量密度和出色循环性能的钠离子全电池证明了δ-α-MnSe负极的适用性。
