Research status of graphene lithium battery technology
Graphite has been the material that could bring technology revolution in lithium battery industry. The charging or discharging speed of lithium battery with graphite negative electrode material is 10 times faster than conventional one, which will undoubtedly improve the energy efficiency of the power battery greatly.what are the breakthroughs for the application of graphene in lithium batteries at this stage?
University of California, Los Angeles, the United States made porous three-dimensional graphene;architecture
A graphite UCLA team prepared some kind of graphene aerosol, and converted graphite;alkenyl;into an aerosol solvated graphite;alkeny dimensional porous architecture in a simple way, greatly enhance the conductivity and the lithium ion-exchange.To prepare the graphite alkenylarchitecture, scientists have an improved hydrothermal method, using oxide graphene form graphite free and unsupported graphene aerosol cube.By simple solvent substitution, they converted into aerosol structure into three-dimensional aerosol graphene structure.Then, they could easily press it to a thin film and putted into the lithium ion button battery, without impairing the porous graphite alkenyl network structure.This simple-produced anode not only make the lithium ion penetration faster but also maintain the graphite alkenyl large surface area and excellent conductivity. Research shows that solvated porous three-dimensional graphite alkenyl aerosol structure has better electrochemical performance.
Korea Research Team invented three-dimensional graphitealkenylmaterial
for improvinglithiumion batteries
The new graphite ion batteryalkenylelectrode material invented by Korea Institute of Science and Technology (KAIST) research team which applied inlithium battery, charge faster than the conventionallithiumcompared ion battery without capacity reduction.According to the team, traditional graphene is atwo-dimensionalsheet ofcarbon atoms. The preparation method is usually to dissolve graphite in a chemical solution and then separate the graphite into ultra-thin sheet carbon materials.Grapheneprepared by this methodwillleave a small amount of impuritieson thecarbon sheet material.Impurities in the material will reduce the battery capacitance after a certain period of use.The team used a chemical deposition method to prepare alamellar carbon materialinthree dimensionswithout any impurities.Compared with the conventional production method, graphite alkenyl material produced by new method does not contain any impurities and the speed of battery recharging is significantly improved.Relevant tests have confirmed that after the prepared battery has undergone 10,000 recharge cycles, no capacitance reduction has occurred.
scientists’ hydrogenationof 3D graphenenano foamelectrodes improves battery performance
Lawrence Livermore National Laboratory (LLNL) research team found after numerous experiments and calculations, in a lithium ion battery (LIBs), by processing the three-dimensional graphitealkenylnano foam electrode hydrogenation can significantly improve the battery capacity and transmission performance, which helps graphene-based high-power electricalpolematerials research and development.Various calculations and tests show that team, defect-rich graphiteethylenicallybe deliberately processed by low temperature hydrogen treatment can enhance the rate capacity.Because hydrogen atoms willinteractwith the defectsingraphene, opening up some small openings, promoting the penetration of lithium ions, thereby improving ion transmission.By increasingthe binding degree oflithiumionsnear the boundary wherehydrogen atoms are mosteasily bound, the reversible capacity can also be increased.In order to studythe storage capacity on the lithium ion that graphene defecthydrogenation treatment brought, the research team tried a variety of heating conditions in the process of hydrogen contacting, and studied the three-dimensional graphitealkenylnano foam (GNF) electrochemical properties. These electrodes mainly composed of graphite tape defectalkenylconfiguration.Three-dimensional graphenefoam non-additive characteristics avoid the negative effects brought about by the use of additives. So it is an ideal material.The study showed that of the graphene-based anode material, a controlled hydrogenation treatment can be used as an optimizationof lithiumion transport and effective reversible method of storagemethods.
Scientists put silicon particles in the graphitealkenyl"cage", to enhance silicon – ion anode
The disadvantage of lithium-ion battery anodes made of silicon materials is that the anode is prone to swell, crack, and even react with the battery electrolyte to form a coating that affects the performance of the electrode.To this end,spacerun:yes”science team composed of Stanford University and the US Department of EnergyNLACNational Accelerator Laboratory, designed a simple three-step method, got the silicon anode particles encased in graphenecustomized, this expected to solve the issue.Microscopic graphitealkenylcage is perfectly dimensioned, the size is enough space for silicon particles expand in battery charging process, but at the same time is compact enough to always be brought together with the particles after separation, so that the electrode can continue to maintain high capacity.Further, the flexible, robust graphitealkenylcage also blockingthe harmful chemical reaction between the electrolyte and electrode.Team test results show that graphitealkenylcage effectively enhance the conductive particles, forminga high energy storagepower and chemical stability and improved efficiency.This method can also be applied to other electrode materials, and it is expected to realize a truly low-cost, high-energy-density battery material.To ensure that the graphitealkenylcage function well, need to match the size of silicon particles perfectly.