Høj sikkerhed komposit lithium metal anode er den næste generation af høj energitæthed energilagringsbatteri?
The research group of Professor Zhang Qiang from the Department of Chemical Engineering of Tsinghua University published the paper "Coralloid Carbon Fiber-Based Composite Lithium Anode for Robust Lithium Metal Batteries" in the well-known journal "Joule" in the energy field. Important progress has been made in the field of high-safety and high-capacity composite lithium metal anodes. The research was selected as the cover article of this issue of Joule, and the cover image was published.
Metallithium har ekstremt høj teoretisk specifik kapacitet og det laveste redoxelektrodepotentiale, så det er blevet det mest ideelle anodemateriale til næste-generations høj-energi-densitetsenergiopbevaringsbatterier (næste -generations solid-lithiumbatterier, lithium-svovlbatterier, lithium-luftbatterier osv.). Dendritproblemet under opladning og afladning af metallithium og ustabiliteten af lithium-elektrolytgrænsefladefilmen reducerer imidlertid cykluseffektiviteten af lithiummetalbatterier alvorligt, forkorter batteriets levetid og medfører endda en en vis grad af sikkerhedsrisici. hindre udviklingen af lithiummetalbatterier.
The cover picture uses a metaphor to express the design idea of "composite lithium metal negative electrode". The composite lithium metal negative electrode based on lithiophilic carbon fiber is likened to a ship, which can sail stably in the "ocean" of molten lithium.
For nylig har forskere foreslået en række metalliske lithiumanoder baseret på ledende kulstoframmer eller metalrammer. Mange af disse rammer var dog ikke præ-komplekserede med metallisk lithium, men blev testet i halve-celler som lithium-fri strømaftagere. Sådanne lithium-fri strømaftagere er svære at anvende direkte på hele celler. Derfor er det blevet forskningens fokus, hvordan man effektivt præ-sammensætter lithiummetal i den nuværende kollektorstruktur for at danne en høj-komposit lithiummetalanode, der kan samles direkte til et fuldt batteri.
Som svar på den presserende efterspørgsel efter kompositelektroder i lithiummetalbatterier foreslog forskerholdet af professor Zhang Qiang fra Tsinghua University en negativ lithiummetalelektrode i komposit med koral-som kulfibersmeltet lithium. Overfladen af kulfiberskelettet (CF) modificeres til en lithiofil overflade ved metoden med galvanisering af sølvbelægning, så det flydende smeltede lithiummetal hurtigt kan absorberes i kulfiberskelettet (CF/Ag) med sølvbelægning, så for at opnå høj ydeevne Den sammensatte lithiummetalanode (CF/Ag-Li).
On the one hand, the silver coating can modify any conductive framework into a lithiophilic conductive framework that can siphon liquid molten lithium. Cyclic morphology of "dead lithium". Through the experimental observation of in-situ metallic lithium deposition, it is found that it is difficult to form dendrites in this composite structure. The proposed composite lithium metal anode can be stably cycled for more than 160 cycles with very low polarization under extremely harsh conditions of 10 mAcm-2 and 10 mAhcm-2. Compared with conventional lithium metal anodes, the composite lithium metal anode can withstand extreme areal current density and areal capacity cycling, showing high safety features.
Koral-lignende kulfiber smeltet lithium-fyldt komposit lithiummetalanode
The composite metal lithium negative electrode is directly assembled with the sulfur positive electrode and the lithium iron phosphate positive electrode to form a lithium{{0}}sulfur battery and a lithium iron phosphate battery with excellent performance. Its lithium iron phosphate battery can stably cycle for more than 500 cycles at a rate of 1.0C, while the lithium-sulfur battery has an initial discharge capacity of 781mAhg-1 at 0.5C, and maintains a high-capacity cycle for more than 400 cycles. The conductive skeleton silver-plated lithium-injection method of this work can be universally applied to the design and preparation of any composite metal lithium anode based on the conductive skeleton. Lithium" cycle appearance, and then obtain excellent electrochemical performance in full battery systems such as lithium-sulfur batteries, and improve the safety of energy storage systems.
