| 1. |
- Liang, Huali, et al.
(författare)
-
Highly-ordered microstructure and well performance of LiNi0.6Mn0.2Co0.2O2 cathode material via the continuous microfluidic synthesis
- 2020
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 394
-
Tidskriftsartikel (refereegranskat)abstract
- Ni-rich layered oxides are potential cathode candidate's materials for Li-ion batteries due to their low cost and high energy density. However, it is difficult to reproducibly prepare uniformly distributed element and wellcontrolled morphology of Ni-rich layered oxide particles. This study develops a continuous microfluidic reaction process to synthesize spherical carbonate precursors (Ni0.6Mn0.2Co0.2CO3). The as-synthesized LiNi0.6Co0.2Mn0.2O2 materials exhibit well-defined microsphere morphology, uniform particles size distribution, better thermal stability and homogeneous transition metal distribution, due to the excellent mixing, well mass and heat transfer rate during the microfluidic reaction. Moreover, the as-prepared LiNi0.6Co0.2Mn0.2O2 materials achieve higher initial capacity, excellent electrochemical reversibility and capacity retention than that of the samples prepared by traditional co-precipitation. Therefore, our results demonstrate that microfluidic reaction is a simple and effective synthesis technology for preparing Ni-rich layered cathode.
|
|
| 2. |
- Qiu, Zhengfu, et al.
(författare)
-
Construction of silica-oxygen-borate hybrid networks on Al2O3-coated polyethylene separators realizing multifunction for high-performance lithium ion batteries
- 2020
-
Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 472
-
Tidskriftsartikel (refereegranskat)abstract
- The separator, an essential component in lithium ion batteries, faces more challenges with the increasing diversification of electrode materials towards higher energy density and longer life. Herein we report the performance improvements of lithium ion batteries enabled by the multifunctional separator, which is fabricated by constructing the silica-oxygen-borate (Si-O-B) thin layer on Al2O3-coated polyethylene separators through surface engineering. This separator inherits the advantage of Al2O3-coated polyethylene separators in terms of excellent thermal stability and puncture strength, and no obvious dimensional change at 200 degrees C. The Si-O-B thin layer provides abundant Lewis acid sites and excellent electrolyte uptake to desolvate Li+ ions and traps anions, and therefore favors excellent lithium ion transport properties and lithium/electrolyte interfacial stability. More importantly, the Si-O-B hybrid thin layer endows an additional function of scavenging HF and H2O molecules. The benefits offered by this separator are demonstrated by the enhanced C-rates capability and cycling performance of both LiCoO2/Li half-cell and NCM/graphite full cell, which lies far beyond those achievable with commercial polyethylene separators and Al2O3-coated polyethylene separators. This work presents a simple and efficient strategy to construct multifunctional separators with excellent comprehensive properties, and provides inspiration for the rational design of advanced separators towards next-generation high-performance batteries.
|
|
| 3. |
- Xue, Xiaoyin, et al.
(författare)
-
PEDOT:PSS @Molecular Sieve as Dual-Functional Additive to Enhance Electrochemical Performance and Stability of Ni-Rich NMC Lithium-Ion Batteries
- 2020
-
Ingår i: Energy Technology. - : Wiley. - 2194-4288 .- 2194-4296. ; 8:10
-
Tidskriftsartikel (refereegranskat)abstract
- Molecular sieves (MSs) coated with conductive polymer (PEDOT:PSS) are used as water scavengers to modify the nickel‐rich LiNi1–x–yCoxMnyO2 (NMC)‐layered cathode. This strategy proactively captures residual water in the battery system without affecting the transport performance of electrons and Li+ ions. The moisture content and nuclear magnetic resonance (NMR) tests show that MSs after coating still maintain good water absorption characteristics and inhibit the decomposition of the electrolyte. The conductivity of the PEDOT:PSS@MS‐NMC electrode is 1.08 × 10−4 S cm−1, which is improved by 63.9%, compared with the MS‐NMC electrode. Through X‐ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy measurements, it is also shown that the surface structure stability and particle integrity for PEDOT:PSS@MS‐NMC electrode is well retained. After 500 cycles, the capacity retention of the composite cathode is 71.3%, which is higher than that of the NMC (38.3%) and MS‐NMC cathode (62.4%). This is a novel and effective strategy to suppress side reactions at the electrode interface and improve electrode stability, capacity retention, and cycle performance of the Ni‐rich NMC cathode.
|
|
| 4. |
- Zhai, Pan, et al.
(författare)
-
Ionic Conductive Thermoplastic Polymer Welding Layer for Low Electrode/Solid Electrolyte Interface Resistance
- 2020
-
Ingår i: ACS Applied Energy Materials. - : AMER CHEMICAL SOC. - 2574-0962. ; 3:7, s. 7011-7019
-
Tidskriftsartikel (refereegranskat)abstract
- The application of LAGP ceramic solid electrolytes is circumscribed by the large electrode/electrolyte interfacial resistance because of their rigidity and brittleness. Here, a highly cohesive composite polymer layer consisting of poly(vinylene carbonate)-thermoplastic polyurethanes (PVC-TPU) is coated onto both sides of the Li1.5Al0.5Ge1.5(PO4)(3) pellet to address the interfacial problems with the electrodes. The coated PVC-TPU acts as an ionic conductive welding layer to facilitate the interfacial contact of the LAGP pellet with both electrodes and decreases the interfacial resistance of the LAGP pellet against the cathode (from 1.4 x 10(6) to 3.8 x 10(3) Omega cm(2)) and the Li-metal anode (from 3.3 x 10(4) to 890 Omega cm(2)). The resulting composite solid-state electrolyte (CSSE) presents the synergistic effect of the LAGP ceramic pellet and the PVC-TPU layer in terms of electrochemical stability, ionic transport properties, and stable lithium plating/stripping cycling with a low overpotential for 1000 h. Consequently, the LiFePO4/Li solid-state batteries utilizing this CSSE deliver a high capacity retention of 95.3% after 100 cycles at room temperature with a high Coulombic efficiency exceeding 99.99% per cycle and lithium dendrite inhibition.
|
|
