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Hybrid ionic thermoelectric and photocatalytic materials(i-TEPC):a new choice for energy harvesting

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Science China Chemistry 2024年第7期67卷 2127-2129页

作者： qikai li Mao Yu Weishu liu Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

Ionic thermoelectric(i-TE)material is a kind of new functional material that can convert heat energy into electric energy,which is of great significance for renewable energy technologies and sustainable development[1].The fundamental constitution of i-TE material mainly comprises an electrolyte matrix,ion providers and redox pairs.

关键词： energy harvesting convert

Rethinking atomic packing and cluster formation in metallic liquids and glasses

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Chinese Science Bulletin 2011年第36期56卷 3897-3901页

作者： li qikai li Mo Department of Mechanical Engineering Tsinghua University Beijing 100084 China School of Material Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA

In traditional view,atomic packing is random in glasses made of metallic elements with non-directional interactions as the glass-forming liquid needs to be excited to remain in liquid state before being cooled sufficiently fast to a glass. Locally ordered packing however is possible if certain conditions are favorable,such as a strong bonding between elements,or low configuration energy of a cluster of atoms as suggested by Frank. In alloy systems made of different metallic elements,we show that Frank's criterion alone does not necessarily lead to certain specific local ordered packing or cluster formation such as icosahedral packing. In this context,we revisit the issue of atomic packing and cluster formation,and show that an alloy system with fairly random liquid configuration could be sufficient to produce a variety of noticeable locally ordered packing with low energy,albeit largely statistical in nature. Therefore,we emphasize the importance of the system parameters such as the atomic size,alloy concentration,and interaction potential in their collective contribution to local atomic packing.

关键词：金属液体原子群包装集群眼镜合金系统金属元素玻璃形成

Enhanced thermoelectric performances of flexible PEDOT:PSS film by synergistically tuning the ordering structure and oxidation state

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Journal of Materiomics 2020年第1期6卷 119-127页

作者： qikai li Qing Zhou Long Wen Weishu liu Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen518055China Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices Southern University of Science and TechnologyShenzhen518055China

Flexible polymer thermoelectric thin film attracts wide attentions because it is compatible with the wearable electronics and ***,we reported an enhanced thermoelectric power factor of PEDOT:PSS from around 1 μWm^(-1) K^(-2) to 117 μWm^(-1) K^(-2) and high substrate-free strain of 20% through synergistically tuning the ordering structure and the oxidation *** ionic liquid(EMImTCM)was used to decouple the ionic interaction between PEDOT and PSS,rearranging the morphology of structure that significantly benefit the mechanical flexibility and the electrical *** addition of Lascorbic acid was confirmed as effective dedoping additive of PEDOT polymer that changed the oxidation state and hence boosted the thermoelectric power factor without notable sacrifice of the mechanical ***,the electrical conductivity of the corresponding film maintained electrically stable(ΔR/R_(0)lity to controllably tailor the thermoelectric and mechanical performance of the PEDOT:PSS flexible polymer thermoelectric thin film.

关键词： PEDOT:PSS Ordering Oxidation level Thermoelectric Flexibility

One-Dimensional Fractal Curves and Fractal Dimension Determination

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 165-168页

作者： qikai li Yue Zhang Wuyang Chu(Applied Science School, University of Science and Technology Beijing, Beijing 100083, China) Applied Science School University of Science and Technology Beijing Beijing 100083 China

Various methods for evaluating the fractal curves were reviewed and simulated on computer. It is shown box-counting and power spectrum methods generally give poor measuring results, while yard and variation methods could obtain good results. However,owing to multiple influencing factors, further study needs to be done before widespread application of variation method. In order to improve the measuring accuracy of yard method, a new method has been propoed to measure the fractal dimension by changing the instrumental resolutions.

关键词： fractal fractal dimension computer simulation

Polaron interfacial entropy as a route to high thermoelectric performance in DAE-doped PEDOT:PSS films

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National Science Review 2024年第3期11卷 259-270页

作者： Jiajia Zhang Caichao Ye Genwang Wei liang Guo Yuhang Cai Zhi li Xinzhi Wu Fangyi Sun qikai li Yupeng Wang Huan li Yuchen li Shuaihua Wang Wei Xu Xuefeng Guo Wenqing Zhang Weishu liu Department of Materials Science and Engineering Southern University of Science and Technology Academy for Advanced Interdisciplinary Studies and Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology Department of Mechanical and Energy Engineering Southern University of Science and Technology Beijing National Laboratory for Molecular Sciences Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences College of Chemistry and Molecular Engineering National Biomedical Imaging Centre Peking University Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology

Enhancing the thermoelectric transport properties of conductive polymer materials has been a long-term challenge, in spite of the success seen with molecular doping strategies. However, the strong coupling between the thermopower and the electrical conductivity limits thermoelectric performance. Here, we use polaron interfacial occupied entropy engineering to break through this intercoupling for a PEDOT:PSS(poly（3,4-ethylenedioxythiophene）-poly（4-styrenesulfonate）) thin film by using photochromic diarylethene（DAE） dopants coupled with UV-light modulation. With a 10-fold enhancement of the thermopower from 13.5 μV K-1to 135.4 μV K-1and almost unchanged electrical conductivity, the DAE-doped PEDOT:PSS thin film achieved an extremely high power factor of 521.28 μW m-1K-2from an original value of 6.78 μW m-1K-2. The thermopower was positively correlated with the UV-light intensity but decreased with increasing temperature, indicating resonant coupling between the planar closed DAE molecule and PEDOT. Both the experiments and theoretical calculations consistently confirmed the formation of an interface state due to this resonant coupling. Interfacial entropy engineering of polarons could play a critical role in enhancing the thermoelectric performance of the organic film.

关键词： thermoelectric PEDOT: PSS interfacial occupied entropy resonant coupling UV-light modulation

Organic dyes based on triphenylamine for dye-sensitized solar cells:Structure–property relationships

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Journal of Energy Chemistry 2016年第4期25卷 615-620页

作者： Huixia Shang qikai li Kejian Jiang Xiaowei Zhan Handan Key Laboratory of Organic Small Molecule Materials Handan University Institute of Chemistry Chinese Academy of Sciences Department of Materials Science and Engineering College of EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationPeking University

Three new organic dyes based on triphenylamine with a structure of A-D-A-D-A (D1), A-D-A (D2) and D-A (D3) were designed, theoretically calculated and synthesized for dye-sensitized solar cells. Dye D1 exhibits a broader absorption than D2 and D3, due to the intramolecular charge transfer between the donor triphenylamine and the acceptor benzothiadiazole. Dye D1 exhibits a lower HOMO and a lower LUMO than D2 and D3 due to the electron-withdrawing benzothiadiazole. The number of anchoring group cyanoacrylic acid has no obvious influence on absorption and energy levels of D2 and D3. The LUMO of D1 locates on benzothiadiazole rather than cyanoacrylic acid anchoring groups, while the LUMOs of D2 and D3 are localized on cyanoacrylic acid. D2 and D3 give higher short-circuit current density than D1. D3 with one anchoring group gives the highest open-circuit voltage. Consequently, the D3-based device gives the highest efficiency. © 2016 Science Press

关键词： Charge transfer Open circuit voltage Reconfigurable hardware Solar cells

Anionic entanglement-induced giant thermopower in ionic thermoelectric material Gelatin-CF_(3)SO_(3)K–CH_(3)SO_(3)K

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eScience 2023年第5期3卷 105-112页

作者： qikai li Cheng-Gong Han Shuaihua Wang Cai-Chao Ye Xinbo Zhang Xiao Ma Tao Feng Yuchen li Weishu liu Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhenGuangdong 518055China Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices Southern University of Science and TechnologyShenzhen 518055China Department of Mechanical Engineering The University of Hong KongPokfulam Road 999077Hong KongChina Center for Advanced Analytical Science Guangzhou Key Laboratory of Sensing Materials and DevicesGuangdong Engineering Technology Research Center for Photoelectric Sensing Materials and DevicesSchool of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou 510006China

Ionic thermoelectric(i-TE)technologies can power Internet of Things(IoT)sensors by harvesting thermal energy from the environment because of their large *** research focuses mostly on using the interactions between ions and matrices to enhance i-TE performance,but i-TE materials can benefit from utilizing different methods to control ion ***,we introduced a new strategy that employs an ion entanglement effect.A giant thermopower of 28 mV K^(-1)was obtained in a quasi-solid-state i-TE Gelatin-CF_(3)SO_(3)K–CH_(3)SO_(3)K gel via entanglement between CF_(3)SO_(3)^(-)and CH_(3)SO_(3)^(-)*** anionic entanglement effect involves complex interactions between these two anions,slowing anionic thermodiffusion and thus suppressing bipolar effects and boosting p-type thermopower.A Au@Cu|Gelatin-CF_(3)SO_(3)K–CH_(3)SO_(3)K|Au@Cu i-TE device with a generator mode delivers a specific output energy density of 67.2 mJ m^(-2)K^(-2)during 2 h of ***-term operation.

关键词： Thermopower Thermodiffusion Ion interactions Energy harvesting Gelatin

A New Method for Fractal Dimension Determination by STM at Nanometer Scale

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 64-68页

作者： qikai li Yue Zhang Wuyang Chu Chen Wang Chunli Bai (Applied Science School. University of Science and Technology Beijing, Beijing 100083. China)(Chemical Institute, Chinese Academy of Science, Beijing 100080. China) Applied Science School University of Science and Technology Beijing Beijing 100083 China Chemical Institute Chinese Academy of Science Beijing 100080 China

A new method for determining the fractal dimension by STM at nanomeler scale has been ***- Mandelbrot fractal curves were used to verify the accuracy and reliability. The Computer simulation showed that fractal dimen- sion obtained with this method generally outran the traditional yard method. The new method has been applied to the fractal dimension determination of the fractures of Ti3Al and Ti-24Al-11Nb alloys. The results show that the fractal dimension of Ti-24Al-11Nb alloy is higher than that of Ti3Al, and it varies with the crark extending orientation.

关键词： fractal dimension STM nanometer scale Ti-Al alloy

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高速冲击压缩梯恩梯的分子动力学模拟

力学学报 2015年第1期47卷 174-179页

作者：刘海李启楷何远航北京理工大学爆炸科学与技术国家重点实验室北京100081 清华大学材料学院北京100086

采用反应力场分子动力学方法模拟了梯恩梯(2,4,6-trinitrotoluene,TNT)冲击压缩过程.冲击压缩完全时,体积压缩至原体积40%,梯恩梯分子分解完毕,体系压力达到峰值.随后稀疏波反向拉伸致大量原子或分子基团飞溅至下游,同时压力开始卸载.... 详细信息

采用反应力场分子动力学方法模拟了梯恩梯(2,4,6-trinitrotoluene,TNT)冲击压缩过程.冲击压缩完全时,体积压缩至原体积40%,梯恩梯分子分解完毕,体系压力达到峰值.随后稀疏波反向拉伸致大量原子或分子基团飞溅至下游,同时压力开始卸载.密度及粒子速度剖面显示压缩波后方密度较大,粒子基本处于静止状态,且压缩波内存在较大的粒子速度梯度.早期化学反应特征是梯恩梯分子在冲击压缩作用下脱落H,O原子后残基快速聚合形成较大的分子团簇,此阶段和平动-振动弛豫过程相关,并且分子由平动—振动模态转换的时间尺度为0.5 ps.产物识别分析显示梯恩梯在高速冲击压缩下致C—H,O==N键断裂,脱落的原子部分形成OH,H2,H2O,N2,部分H,O原子游离在体系中.含碳团簇分析显示,冲击压缩作用致体系中含碳团簇的摩尔质量逐渐累积.体系内含碳团簇中O/C,H/C,N/C原子数量比值逐渐趋于平衡(O/C=0.680,H/C=0.410,N/C=0.284),且均小于初始结构中的比值.

关键词：冲击压缩梯恩梯反应力场分子动力学