You can easily achieve what you want using the appendix
package. Here's a sample file that shows you how. The key is the titletoc
option when calling the package. It takes whatever value you've defined in \appendixname
and the default value is Appendix
.
\documentclass{report}
\usepackage[titletoc]{appendix}
\begin{document}
\tableofcontents
\chapter{Lorem ipsum}
\section{Dolor sit amet}
\begin{appendices}
\chapter{Consectetur adipiscing elit}
\chapter{Mauris euismod}
\end{appendices}
\end{document}
The output looks like