Prelithiation strategy enhances battery performance at low temperatures
When it is cold in winter, cars tend to have starting problems. This is not much better with electric cars, which inevitably lose capacity of their rechargeable lithium-ion batteries at freezing temperatures. Now, Chinese scientists have offered a strategy to avoid plunging battery kinetics. In a study they designed a battery system with a cold-enduring hard-carbon anode and a powerful lithium-rich cathode, with the important initial lithiation step integrated.
© Wiley-VCH
“Non-graphitizable” or “hard” carbon is a promising, low-cost anode material in battery technology. Even at low temperatures, it exhibits fast intercalation kinetics of lithium ions. During charging/discharging of a battery cell, lithium ions migrate from the cathode through an electrolyte to the anode and vice versa. If the anodic material, which is often graphite, contains prestored lithium, the volume change by the incoming lithium ions is leveled out to ensure a longer cell life and faster charge/discharge kinetics. Prelithiated hard carbon has been proven as a robust material in lithium-ion capacitors. However, the prelithiation process, which involves a pure lithium electrode, is complicated and expensive. Alternative prelithiation strategies are therefore favored by Yonggang Wang and his team at Fudan University, Shanghai, China.
Instead of the extra lithium electrode, they introduced a lithium-rich vanadium phosphate electrode both for lithiation and normal battery operation. The cathode loses some of its lithium ions to the anode in the first charging process where they are intercalated and stored. Then, the scientists combined the lithium-reduced vanadium phosphate cathode and the prelithiated hard-carbon anode (LixC) to form a working lithium-ion battery system. This full cell “keeps the high energy density characteristics of conventional lithium-ion batteries and exhibits the supercapacitor-like high power and long cycle life,” the scientists explained. Moreover, it keeps about two-thirds of its capacity at temperatures as low as minus 40 degrees Celsius. Conventional lithium-ion batteries retain only 10 percent. “This achievement arises from the inherent low-temperature ability of the vanadium phosphate cathode and the fast kinetics of the prelithiated hard-carbon anode,” said the authors. Many further tests showed that these batteries fulfilled the other parameters of electrochemical cells.
A flaw, still, is the electrolyte that loses conductivity under extremely cold conditions. If this point is solved, this system might provide an attractive design for best performance, winter-enduring electric car engines.
Original publication
Other news from the department science
![[Fe]-hydrogenase catalysis visualized using para-hydrogen-enhanced nuclear magnetic resonance spectroscopy](https://img.chemie.de/Portal/News/675fd46b9b54f_sBuG8s4sS.png?tr=w-712,h-534,cm-extract,x-0,y-16:n-xl)
Get the chemical industry in your inbox
From now on, don't miss a thing: Our newsletter for the chemical industry, analytics, lab technology and process engineering brings you up to date every Tuesday and Thursday. The latest industry news, product highlights and innovations - compact and easy to understand in your inbox. Researched by us so you don't have to.
Most read news
More news from our other portals
See the theme worlds for related content
Topic World Battery Technology
The topic world Battery Technology combines relevant knowledge in a unique way. Here you will find everything about suppliers and their products, webinars, white papers, catalogs and brochures.
Topic World Battery Technology
The topic world Battery Technology combines relevant knowledge in a unique way. Here you will find everything about suppliers and their products, webinars, white papers, catalogs and brochures.
