Li-ion battery materials: present and future

Electrolytes and interphases in Li-ion batteries and beyond.

Energy density is the main property of rechargeable batteries that has driven the entire technology forward in past decades. Lithium-ion batteries (LIBs) now surpass other, previously competitive battery types (for example, lead–acid and nickel metal hydride) but still require extensive further improvement to, in particular, extend the operation hours of mobile IT devices and the driving mileages of all-electric vehicles. In this Review, we present a critical overview of a wide range of post-LIB materials and systems that could have a pivotal role in meeting such demands. We divide battery systems into two categories: near-term and long-term technologies. To provide a realistic and balanced perspective, we describe the operating principles and remaining issues of each post-LIB technology, and also evaluate these materials under commercial cell configurations. Post-lithium-ion batteries are reviewed with a focus on their operating principles, advantages and the challenges that they face. The volumetric energy density of each battery is examined using a commercial pouch-cell configuration to evaluate its practical significance and identify appropriate research directions.

Promise and reality of post-lithium-ion batteries with high energy densities

The storage of electrical energy at high charge and discharge rate is an important technology in today's society, and can enable hybrid and plug-in hybrid electric vehicles and provide back-up for wind and solar energy. It is typically believed that in electrochemical systems very high power rates can only be achieved with supercapacitors, which trade high power for low energy density as they only store energy by surface adsorption reactions of charged species on an electrode material. Here we show that batteries which obtain high energy density by storing charge in the bulk of a material can also achieve ultrahigh discharge rates, comparable to those of supercapacitors. We realize this in LiFePO(4) (ref. 6), a material with high lithium bulk mobility, by creating a fast ion-conducting surface phase through controlled off-stoichiometry. A rate capability equivalent to full battery discharge in 10-20 s can be achieved.

Battery materials for ultrafast charging and discharging

https://las493energy.files.wordpress.com/2014/11/2005_vetter_jpowsourc.pdf

Ageing mechanisms in lithium-ion batteries

The mechanism by which LiFePO 4 is transformed into isostructural FePO 4 has been elucidated using electron microscopy on large, hydrothermally grown LiFePO 4 crystals following chemical delithiation. Lithium is extracted at narrow, disordered transition zones on the ac crystal surface as the phase boundary progresses in the direction of the a-axis. The substantial lattice mismatch along a (ca. 5%) causes crack formation in the bc plane. Despite considerable disorder in the transition zone, the general structural arrangement is preserved, leading to good crystallinity in the newly created FePO 4 domains. Implications for improved electrode performance are discussed.

Electron Microscopy Study of the LiFePO4 to FePO4 Phase Transition

A conductive polymer is developed for solving the long-standing volume change issue in lithium battery electrodes. A combination of synthesis, spectroscopy and simulation techniques tailors the electronic structure of the polymer to enable in situ lithium doping. Composite anodes based on this polymer and commercial Si particles exhibit 2100 mAh g -1 in Si after 650 cycles without any conductive additive. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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Polymers with Tailored Electronic Structure for High Capacity Lithium Battery Electrodes

A comprehensive understanding of electrode thickness effects on the electrochemical performances of Li-ion battery cathodes

https://digital.library.unt.edu/ark:/67531/metadc776905/m2/1/high_res_d/825482.pdf

Xiangyun Song

Papers

Electron Microscopy Study of the LiFePO4 to FePO4 Phase Transition

Polymers with Tailored Electronic Structure for High Capacity Lithium Battery Electrodes

A comprehensive understanding of electrode thickness effects on the electrochemical performances of Li-ion battery cathodes

Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature

Correlation between dissolution behavior and electrochemical cycling performance for LiNi1/3Co1/3Mn1/3O2-based cells