國立高雄大學圖資館 |

語系: 繁體中文

說明(常見問題)

圖資館首頁

登入

回首頁 到查詢結果 [ subject:"Chemical engineering." ]

切換: 標籤 | MARC模式 | ISBD

Electrolyte Engineering to Improve C...

Burke, Colin M.

Electrolyte Engineering to Improve Capacity and Rechargeablility in the Lithium-Oxygen Battery.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Electrolyte Engineering to Improve Capacity and Rechargeablility in the Lithium-Oxygen Battery.
作者:	Burke, Colin M.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, 2018
面頁冊數:	111 p.
附註:	Source: Dissertation Abstracts International, Volume: 80-03(E), Section: B.
附註:	Adviser: Bryan D. McCloskey.
Contained By:	Dissertation Abstracts International80-03B(E).
標題:	Chemical engineering.
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10929983
ISBN:	9780438654297

Electrolyte Engineering to Improve Capacity and Rechargeablility in the Lithium-Oxygen Battery.
Burke, Colin M.

Electrolyte Engineering to Improve Capacity and Rechargeablility in the Lithium-Oxygen Battery. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 111 p.

Source: Dissertation Abstracts International, Volume: 80-03(E), Section: B.

Thesis (Ph.D.)--University of California, Berkeley, 2018.

In this work, the nonaqueous electrolyte of the Li-O2 was engineered toward addressing these challenges and achieving a high-capacity, rechargeable Li-O2 battery. Toward increasing achievable discharge capacity, the ability of electrolytes to induce solubility of the intermediate to Li2O2 formation, lithium superoxide (LiO2), was studied, as this enables a solution mechanism of growth whereby Li 2O2 grows in large, aggregated structures, allowing more Li2O2 to form before cathode passivation. First, the effect of the lithium salt anion on LiO2 solubility was studied. To do so, a typical lithium battery salt, lithium bis(trifluoromethane) sulfonimide (LiTFSI), was partially exchanged for the more strongly electron-donating lithium nitrate (LiNO3) in Li-O2 battery electrolytes. During galvanostatic conditions, a correlation between LiNO3 concentration and discharge capacity was observed. Titrations and scanning electron microscopy of cathodes extracted from discharged batteries confirmed Li2O 2 formation in aggregated structures in cells that partially employed LiNO3 as an electrolyte, indicative of an increase in the solution mechanism with the addition of LiNO3. The increase in LiO 2 solubility was attributed via 7Li NMR to a lower free energy of Li+ in the electrolyte as a result of the addition of the strongly electron donating NO3- in the lithium solvation shell. Differential electrochemical mass spectrometry (DEMS) showed similar oxygen evolution on charge with and without LiNO3, indicating no deleterious effect on cell rechargeability with the addition of LiNO 3.

ISBN: 9780438654297Subjects--Topical Terms:

206267
Chemical engineering.

Electrolyte Engineering to Improve Capacity and Rechargeablility in the Lithium-Oxygen Battery.
LDR:05465nmm a2200313 4500 001 547624
005 20190513114559.5
008 190715s2018 ||||||||||||||||| ||eng d
020 $a 9780438654297
035 $a (MiAaPQ)AAI10929983
035 $a (MiAaPQ)berkeley:18183
035 $a AAI10929983
040 $a MiAaPQ $c MiAaPQ
100 1 $a Burke, Colin M. $3 826983
245 1 0 $a Electrolyte Engineering to Improve Capacity and Rechargeablility in the Lithium-Oxygen Battery.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2018
300 $a 111 p.
500 $a Source: Dissertation Abstracts International, Volume: 80-03(E), Section: B.
500 $a Adviser: Bryan D. McCloskey.
502 $a Thesis (Ph.D.)--University of California, Berkeley, 2018.
520 $a In this work, the nonaqueous electrolyte of the Li-O2 was engineered toward addressing these challenges and achieving a high-capacity, rechargeable Li-O2 battery. Toward increasing achievable discharge capacity, the ability of electrolytes to induce solubility of the intermediate to Li2O2 formation, lithium superoxide (LiO2), was studied, as this enables a solution mechanism of growth whereby Li 2O2 grows in large, aggregated structures, allowing more Li2O2 to form before cathode passivation. First, the effect of the lithium salt anion on LiO2 solubility was studied. To do so, a typical lithium battery salt, lithium bis(trifluoromethane) sulfonimide (LiTFSI), was partially exchanged for the more strongly electron-donating lithium nitrate (LiNO3) in Li-O2 battery electrolytes. During galvanostatic conditions, a correlation between LiNO3 concentration and discharge capacity was observed. Titrations and scanning electron microscopy of cathodes extracted from discharged batteries confirmed Li2O 2 formation in aggregated structures in cells that partially employed LiNO3 as an electrolyte, indicative of an increase in the solution mechanism with the addition of LiNO3. The increase in LiO 2 solubility was attributed via 7Li NMR to a lower free energy of Li+ in the electrolyte as a result of the addition of the strongly electron donating NO3- in the lithium solvation shell. Differential electrochemical mass spectrometry (DEMS) showed similar oxygen evolution on charge with and without LiNO3, indicating no deleterious effect on cell rechargeability with the addition of LiNO 3.
520 $a Second, as anion selection induces the solution mechanism by lowering the free energy of Li+ in solution, non-Li alkali metal cations and alcohols were studied as methods of inducing the solution mechanism by lowering the free energy of the superoxide anion (O2-) in solution. Galvanostatic cycling of Li-O2 batteries containing non-Li alkali metal salts showed a small increase in the achievable discharge capacity, attributed to the softer acidity of non-Li alkali metal cations more favorably solvating the soft base O2-. However, gas analysis of a sodium-oxygen battery with a small amount of Li+ salt added to the battery electrolyte showed Li+ quickly scavenges any non-Li alkali metal cation-associated O2- , and the resultant LiO2 quickly disproportionates into the insoluble Li2O2. It is therefore anticipated that an increase in Li-O2 battery capacity upon the addition of non-Li alkali metal cations is only expected at high currents, when oxygen reduction rates are sufficiently high to allow some O2- to temporarily avoid Li+ in solution. Ppm quantities of methanol, ethanol, and 1-propanol were added to ether-based Li-O2 battery electrolytes as analogues to water, which has been previously shown to induce the solution mechanism due to its strong Lewis acidity lowering the free energy of O2- in solution. The additives induced a two-fold increase in battery capacity, though with little trend in the capacity as a function of the additive's Acceptor Number. These results highlight the complexity of interactions between the constituent species in an electrolyte in terms of their Lewis basicities, Lewis acidities, and other physicochemical properties.
520 $a While the formation of Li2O2 in large aggregated structures increases the achievable discharge capacity, an electrolyte-soluble redox mediator is required to oxidize aggregated Li2O2 on charge and shuttle electrons back to the electrode surface. The rechargeability of Li-O2 batteries containing redox mediators in the presence of water impurities, which are likely difficult to eliminate in practical lithium-air batteries, was studied. Specifically, the effect of water contamination in the electrolyte on the promising redox mediator lithium iodide (LiI) was studied. DEMS and titrations of cathodes extracted from discharged batteries confirmed recent reports that lithium hydroxide (LiOH) formed as the dominant discharge product via a 4 e-/O2 process. However, isotopic labeling and DEMS were used to show LiOH is not reversibly oxidized back to its reactants (Li+, O2, H2O). Rather, titrations, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and galvanostatic cycling of batteries under an argon atmosphere showed charge current in batteries containing both LiI and H2O is a complex mixture of side reactions and redox shuttling. (Abstract shortened by ProQuest.).
590 $a School code: 0028.
650 4 $a Chemical engineering. $3 206267
690 $a 0542
710 2 $a University of California, Berkeley. $b Chemical Engineering. $3 826984
773 0 $t Dissertation Abstracts International $g 80-03B(E).
790 $a 0028
791 $a Ph.D.
792 $a 2018
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10929983