2021 Fiscal Year Annual Research Report
リチウム金属負極の性能向上ために織物テンプレート法で特異構造な銅集電体の開発
| Project/Area Number |
21J21501
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| Allocation Type | Single-year Grants |
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| Research Institution | Hokkaido University |
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Principal Investigator |
朱 瑞傑 北海道大学, 大学院総合化学院, 特別研究員(DC1)
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| Project Period (FY) |
2021-04-28 – 2024-03-31
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| Keywords | channel structures / aligned cotton fibers / lithiophilic / mass-transfer resistance / alleviated inactive Li / enhanced performance |
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| Outline of Annual Research Achievements |
The conductive carbon skeletons with channel structures were obtained by rolling up the aligned cotton fibers and pyrolyzing them.
By using [Cu(NH3)4]2+ to pre-coat a layer of copper-ion (Cu-ion) coating on the cotton fiber, the obtained skeletons would be coated by Cu nanoparticles, which can be easily converted to lithiophilic species, i.e. CuO.
The obtained carbon skeletons were used as the host for Li metal anodes. The channel structure can reduce the mass-transfer resistance at the electrode-electrolyte interface as expected.
At the same time, the vertically aligned channel structure can alleviate the accumulation of inactive Li.
The utilization of the Li metal host indeed enhances the electrochemical performance of Li metal anodes in the aspect of reducing mass-transfer resistance.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The channel structured Li metal host can be prepared as expected, and indeed enhances the performance of Li metal anode.
1. The conductive carbon skeletons with channel structures can be prepared as expected.
2. By melting Li metal and making molten Li metal contact with the conductive carbon skeletons, which are decorated by lithiophilic species, Li metal can be injected directly into the channel of the conductive carbon skeletons. The composite Li metal anode can be prepared as expected.
3. The channel structure can reduce the mass-transfer resistance at the electrode-electrolyte interface as expected, and at the same time, the vertically aligned channel structure can alleviate the accumulation of inactive Li.
Based on these reasons, the research is considered to be well underway.
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| Strategy for Future Research Activity |
As depicted in the research plan, nickel (Ni) skeletons with channel structures will also been prepared by using a similar method.
However, considering that the ideal opening size of the structure is about 100 um, the channel opening size of the Ni skeletons will be reduced during the sintering process, leading to unsatisfactory results. The solution to this problem will be investigated.
If the issue of channel opening size cannot be solved by adjusting the synthesis strategies, other templates will be considered for preparing a host with an ideal pore size.
In addition, using hydrofluoroether-based ether electrolytes as the electrolyte and optimizing the ion-transporting at the Li metal/electrolyte interface by adjusting the host structure will also be carried out in the follow-up research.
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