Green Energy & Environment
·
2020
·Vol. 7
·期 1
·53-65
·
IF 6.395
Hong-Li Ding,Hai-Tao Yu,Xiao-dong Wang,Chen-Feng Guo,Bing Zheng,Ying Xie,Ting-Feng Yi
SrLi 2 Ti 6 O 14 (SLTO) coated with different amount of ZrO 2 was successfully prepared. The as-obtained composites are stacked by a series of particles with a pure phase structure and a good crystallinity. Furthermore, ZrO 2 coating not only enhances the structural stability of the materials but also facilitates the diffusion of lithium through the SEI film. As a result, the redox polarization was reduced, and the reversibility of the electrochemical reaction was enhanced. Particularly, SLTO-ZrO 2 -2 sample delivers a high initial lithiation capacity of 283.6 mA h g −1 , and the values maintain at 251.7, 228.0, 207.4, 175.3, and 147.7 mA h g −1 at the current densities of 0.13, 0.26, 0.54, 1.31, and 2.62 A g −1 , respectively. Our experiment also confirmed that SLTO materials coated with ZrO 2 are suitable for high power density applications, and the lithiation specific energy efficiency of SLTO-ZrO 2 -2 is 200% as high as that of pure SLTO at a power density of 1257 W kg −1 .
研究领域:
材料科学
·
电化学
·
能源存储
·
无机非金属材料
·
固态离子学
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2019
·
IF 2.781
Yunjiao Li,Shilei Wang,Yongxiang Chen,Tongxing Lei,Shiyi Deng,Jie Zhu,Jinping Zhang,Jia Guo
Cadmium oxides (CdO), an important semiconductor material , have many superior properties when used as a cathode material for nickel-cadmium batteries. Here, the coating and the doped co-modified LiNi 0.8 Co 0.15 Al 0.05 O 2 cathode are constructed by a continuous wet chemical process and a high-temperature sintering process, wherein the Cd 2+ are uniformly doped in a gradient form and the CdO protective layer is distributed on the outer surface of secondary particles. The Cd-modified NCA material has more stable interfacial and crystal lattice structure, thereby inhibiting harmful phase transitions and side-reactions. Accordingly, the modified sample has excellent electrochemical performance and maintaining a complete spherical morphology during long cycling compared to the pristine sample. In addition, as a pillar ion, cadmium increases the plate spacing and lithium-ion diffusion kinetics. The electrochemical results show that the capacity retention of the modified sample Cd-2000 reached 96.5% and 90.6% after 100 cycles and 200 cycles respectively at 1 C. At the high current rate of 8 C, the initial capacity and retention (100 cycles, 3.0–4.3 V) reach 166.2 mAh g −1 and 95.2%, respectively. Besides, the results of electrochemical impedance spectroscopy (EIS) reveal that CdO modification could decrease the resistance of the cell polarization and impedance increment upon cycling.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
半导体材料
✓ 已验证
DOI
高影响因子
Small
·
2019
·Vol. 15
·期 50
·1904854
·
IF 10.856
Junchao Zheng,Zhuo Yang,Alvin Dai,Linbo Tang,Hanxin Wei,Yunjiao Li,Zhenjiang He,Jun Lu
Although the high energy density and environmental benignancy of LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) holds promise for use as cathode material in Li-ion batteries, present low rate capabilities, and fast capacity fade limit its broad commercial applications. Here, it is reported that surface modification of NCA cathode ( R-3m ) with 5 nm-thick nanopillar layers and Fm-3m structures significantly improves electrode structure, morphology, and electrochemical performance. The formation of nanopillar layers increases cycling and working voltage stability of NCA by shielding the host material from hydrofluoric acid and improves structural stability with the electrolyte. The modified NCA cathode exhibits an enhanced 89% capacity retention at a rate of 1 C over that of pristine NCA (75.2%) after 150 cycles and effectively suppresses working voltage fade (a drop of 0.025 V after 300 cycles) during repeated charge–discharge cycles. In addition, the diffusion barrier of Li ions in NCA crystals at 0.80 V is noticeably smaller than that of Li ions in pristine NCA (0.87 eV). These findings demonstrate that this unique surface structure design considerably enhances cycle and rate performance of NCA, which has potential applications in other Ni-rich layered cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
锂离子电池
·
纳米材料
✓ 已验证
DOI
高影响因子
Nano Energy
·
2020
·
IF 16.602
Long Li,Chun Fang,Wenfei Wei,Lei Zhang,Zhao Ye,Gang He,Yunhui Huang
The huge volume change of silicon anode during cycling results in unstable solid electrolyte interface (SEI), causing rapid performance degradation . Natural SEI layer has a heterogeneous structure, results in the inhomogeneous Li + diffusion. The repeated destruction and regeneration of SEI aggravate the inhomogeneity of Li + diffusion at the interface, leading to non-uniform alloy reaction in the Si bulk. In this work, the silicon surface is passivated by an ultrathin uniform chitosan layer with abundant lithiophilic groups. The capacity of chitosan-coated Si (Si@CS) could reach 1500 mAh g −1 at a current density of 1 A g −1 , and the capacity retention remains 91% after 400 cycles. It is demonstrated that the oxygen and nitrogen atoms in chitosan are coordinated with Li + , providing uniformly distributed Li + transfer sites, results in a homogeneous Li + flux in the surface layer. Interestingly, a nano-scale ordered atomic arrangement is observed in the delithiated Si@CS, which contributes to more stable and reversible lithiation/delithiation reaction of the Si@CS electrode. It is proposed that optimizing the reaction interface on the Si surface is able to alter the Li-ion diffusion kinetics and structure transition behavior of silicon, which can improve the structure reversibility and stability during cycling.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
表面工程
·
锂离子电池
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Peng Li,Lianyi Shao,Pengfei Wang,Xi Zheng,Haoxiang Yu,Shangshu Qian,Miao Shui,Nengbing Long,Jie Shu
In this work, Li 2 NaV 2 (PO 4 ) 3 is successfully synthesized by using a simple solid-state reaction method. Structural analysis shows that this sample is a hybrid product consisted of rhombohedral Li 3 V 2 (PO 4 ) 3 phase and rhombohedral Na 3 V 2 (PO 4 ) 3 phase As a cathode material for lithium ion batteries, Li 2 NaV 2 (PO 4 ) 3 exhibits an initial reversible capacity of 108.9 mAh g −1 at 35 mA g −1 in the potential range between 3.0 and 4.3 V, with an average working potential at 3.75 V. The lithium-ion diffusion coefficient in Li 2 NaV 2 (PO 4 ) 3 is measured to be 1.86–3.27 × 10 −15 cm 2 s −1 . In addition, the electrochemical reaction between Li 2 NaV 2 (PO 4 ) 3 and Li is also investigated by various in-situ and ex-situ techniques. Viewed from the in-situ and ex-situ results, it is concluded that the electrochemical reactions of Li 2 NaV 2 (PO 4 ) 3 with Li are associated with the formation of rhombohedral LiV 2 (PO 4 ) 3 phase and rhombohedral NaV 2 (PO 4 ) 3 phase during the lithium ion extraction process and its reverse lithium insertion process is reversible for structural evolution. The highly stable structure ensures the electrochemical reversibility of Li 2 NaV 2 (PO 4 ) 3 cathode material in lithium ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2017
·
IF 3.012
Haojie Zhu,Ke Yang,Hua Lan,Shangshu Qian,Haoxiang Yu,Lei Yan,Nengbing Long,Miao Shui,Jie Shu
In this work, Na 2 Ti 3 O 7 is fabricated as lithium storage material via one-step solid state reaction. Worked as anode material , Na 2 Ti 3 O 7 delivers a stable electrochemical performance with good lithium storage capability. Structural analyses show that Na 2 Ti 3 O 7 anode experiences slight volume change during electrochemical lithiation/delithiation process. Moreover, the reversibility of structural evolution is further demonstrated by in-situ X-ray diffraction technique . All these evidences prove the cycling stability of Na 2 Ti 3 O 7 as lithium storage material. Besides, the kinetic properties of the Li + ion storage in Na 2 Ti 3 O 7 are systematically investigated. The observed results reveal that Na 2 Ti 3 O 7 delivers the lithium ions diffusion coefficient in the range of 10 − 14 –10 − 12 cm 2 s − 1 during the discharge process and 10 − 15 –10 − 12 cm 2 s − 1 during the recharge process. It suggests that Na 2 Ti 3 O 7 has good lithiation/delithiation kinetics in rechargeable batteries.
研究领域:
电化学
·
材料科学
·
能源存储
·
无机化学
·
固体化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）